AO Smith A.O. Smith GT15-510U-O Signature Series 10-GPM User Manual

Gas Tankless Water Heater

Suitable for combination potable water heating

and space-heating

Please refer to local codes

for space-heating compliance.

FEATURING

• ENDLESSHOTWATER

• ON-DEMANDUSAGE

• COMPACT,SPACESAVING

• ENERGYCONSERVATION

• COMPUTERIZEDSAFETY

• NOPILOTLIGHT

• ComplieswithSCAQMDRule

1146.2forNOxemissionsrequire-

mentof14ng/Jor20ppm

• FIELDGASCONVERTIBLE

• EASY-LINK SYSTEM AND MULTI-

UNITSYSTEM

(510U only)

Ifyouhaveanyquestions,please

callorwriteto:

500TennesseeWaltzParkway

AshlandCity,TN37015

TollFree:1-877-737-2840

On-Demand Water Heater

Installation Manual and Owner’s Guide

Keep this manual near the water heater for future reference whenever maintenance, adjustment, or

serviceisrequired.

ANSI Z21.10.3 ・ CSA 4.3

510U only

Models

• 110U Outdoor

• 310U Outdoor

• 510U Outdoor

• 110U Indoor

• 310U Indoor

• 510U Indoor

Series 200

- Do not store or use gasoline or other

flammable vapors and liquids in the vicinity

of this or any other appliance.

- WHAT TO DO IF YOU SMELL GAS

 • Donottrytolightanyappliance.

 • Donottouchanyelectricswitch,donot

use any phone in your building.

 • Immediatelycallyourgassupplierfrom

aneighbor'sphone.Followthegas

supplier's instructions.

 • Ifyoucannotreachyourgassupplier,call

the fire department.

- Installation and service must be performed

byaqualifiedinstaller,serviceagencyorthe

gas supplier.

WARNING

If the information in these

instructions is not followed

exactly,afireorexplosionmay

resultcausingpropertydamage,

personal injury or death.

2 Page

CONTENTS

Installation Manual

SPECIFICATIONS .............................................4

INTRODUCTION ..........................................5

SAFETY GUIDELINES.....................................6

SAFETY DEFINITION ....................................6

GENERAL ......................................................6

INSTALLATION ................................................7

GENERAL ......................................................7

CLEARANCES ...............................................9

INCLUDED ACCESSORIES ............................9

OPTIONAL ITEMS ........................................ 9

WARNING FOR INSTALLATIONS ...............11

HIGH-ALTITUDE INSTALLATIONS .............12

VENTING INSTRUCTIONS .........................13

General .....................................................13

Combustion Air Supply .............................15

Vent length and No. of Elbows .................19

DIP switch settings for Vent length ..........20

Clearances for sidewall terminations .......23

Clearances for rooftop terminations ........24

Vent termination clearances ....................25

GAS SUPPLY AND GAS PIPE SIZING ......... 26

General .....................................................26

Gas connections .......................................26

Natural Gas Supply Piping ........................27

Propane (LP) Supply Piping .......................27

WATER CONNECTIONS .............................28

Pressure relief valve .................................28

ELECTRICAL CONNECTIONS .....................29

TEMPERATURE REMOTE CONTROLLER .....30

Included accessories .................................30

Installation ................................................30

EASY-LINK SYSTEM .........................................32

Easy link connection procedures ..............32

MULTI-UNIT SYSTEM ......................................34

APPLICATIONS ..............................................35

SPACE HEATING APPLICATIONS .. ............. 35

RECIRCULATION ........................................35

DUAL-PURPOSE HOT WATER HEATING ...... 36

INITIAL OPERATION .....................................37

Owner's Guide

OPERATING SAFETY .....................................39

NORMAL OPERATION ..................................41

BUILT-IN CONTROLLER

AND REMOTE CONTROLLER ..................41

GENERAL ....................................................41

TEMPERATURE SETTINGS ........................42

TEMPERATURE SETTINGS ON THE PCB ........44

FLOW .......................................................... 44

FREEZE PROTECTION SYSTEM ................. 45

MAINTENANCE AND SERVICE ................. 45

Measuring inlet gas pressure ...................46

UNIT DRAINING AND FILTER CLEANING .......46

TROUBLESHOOTING .....................................47

GENERAL ....................................................47

ERROR CODES ...........................................49

COMPONENTS DIAGRAM ............................53

PARTS LIST .................................................... 57

OUTPUT TEMPERATURE CHART ..................60

Contents

3 Page

Installaon Manual

Installation Manual

CONGRATULATIONS

Congratulations and thank you for choosing our tankless water heater.

Before use, we recommend that you read through this installation

manual carefully. Keep this manual for future reference.

If you need an additional manual, contact the manufacturer or your

local distributor. When you call, please tell us the product name and

the serial number of your unit written on the rating plate of the water

heater.

4 Page

Specicaons

Installaon Manual

Model

110U

Indoor

110U

Outdoor

310U

Indoor

310U

Outdoor

510U

Indoor

510U

Outdoor

Natural Gas Input

(Operating Range)

BTU/h

Min.: 15,000

Max.: 140,000

Min.: 15,000

Max.: 190,000

Min.: 15,000

Max.: 199,000

Gas Connection 3/4" NPT

Water Connections 3/4" NPT

Water Pressure*

psi

(Mpa)

15 - 150 (0.1 - 1)

Natural gas

Inlet Pressure

" W.C.

(kPa)

Min. 4.0 (1.00)

Max. 10.5 (2.61)

Weight lbs. (kg) 37.5 (17.0) 39.7 (18.0)

Dimensions

Indoor

H 20.5 x W 13.8 x D 9.1 (Inch)

H 520 x W 351 x D 231 (mm)

Outdoor

H 20.5 x W 13.8 x D 8.5 (Inch)

H 520 x W 351 x D 216 (mm)

Ignition Electric Ignition

Electric

Supply VAC / Hz 120 / 60

Consumption

Operation W / A 54 / 0.64 79 / 0.99 82 / 1.02

Standby W / A 2 / 0.06 2 / 0.06 3 / 0.07

Freeze-

Protection

W / A 96 / 0.82 96 / 0.82 97 / 0.82

Water heater category**

Category

III

N/A

SPECIFICATIONS

*40 psi or above is recommended for maximum flow.

**Water heater Category — water heaters of other than direct vent type, for outdoor installation, are divided into four

categories based on static pressure produced in the vent and flue loss.

Category I - a water heater that operates with a non-positive vent static pressure and with a vent gas temperature

that avoids excessive condensate production in the vent.

Category II - a water heater that operates with a non-positive vent static pressure and with a vent gas temperature

that may cause excessive condensate production in the vent.

Category III - a water heater that operates with a positive vent static pressure and with a vent gas temperature that

avoids excessive condensate production in the vent.

Category IV - a water heater that operates with a positive vent static pressure and with a vent gas temperature that

may cause excessive condensate production in the vent.

***These are equivalent lengths that include head loss for elbows, tees, unions, etc.

NOTE:

• Check the rating plate to ensure that this product matches your specifications.

• The manufacturer reserves the right to discontinue, or change at any time, specifications or designs

without notice and without incurring obligation.

5 Page

INTRODUCTION

• This manual provides information necessary for the installation, operation, and maintenance

of the water heater.

• The model description is listed on the rating plate which is attached to the side panel (Indoor

models) or the front cover (Outdoor models) of the water heater.

• Please read all installation instructions completely before installing this product.

• If you have any problems or questions regarding this equipment, consult the manufacturer or

its local representative.

• This appliance is an on-demand, tankless water heater. It is designed to efficiently supply

endless hot water for your needs.

• The 110U Indoor, 310U Indoor, and 510U Indoor models are only to be installed indoors. The

110U Outdoor, 310U Outdoor, and 510U Outdoor models are only to be installed outdoors.

• The principle behind tankless water heaters is simple:

Burners

Hot water xture

Exhaust vent

Heat exchanger

Gas valves

Fan motor

Flow adjustment valve

Computer board

Thermistor

Cold water inlet

Hot water outlet

Gas inlet

Thermistor

Burners

Flow sensor

Igniter

Intake vent

*This diagram illustrates tankless water heater design concepts only and does not accurately represent

the water heater’s physical description.

1. A hot water fixture is turned on.

2. Water flows through the heater.

3. The water flow sensor detects the water flow.

4. The computer initiates the fan motor and gas valve to let gas flow through the heater and sends a

signal to the igniter to create an ignition spark.

5. The gas ignites and flames appear within the burner chamber.

6. Water is heated as it flows through the heat exchanger.

7. Using thermistors to measure temperatures throughout the water heater, the computer modulates

the gas and water valves to ensure proper output water temperature and hot water outflows.

8. When the fixture is turned off, the unit shuts down.

Introducon

Installaon Manual

6 Page

SAFETY GUIDELINES

SAFETY DEFINITION

WARNING

Indicates an imminently hazardous situation which, if not avoided, could result in death or seri-

ous injury.

CAUTION

Indicates an imminently hazardous situation which, if not avoided, could result in minor or

moderate injury.

Indicates an imminently hazardous situation which, if not avoided, will result in death or serious

injury.

DANGER

Indicates information considered important but not hazard related.

NOTICE

GENERAL

1. Follow all local codes, or in the absence of local codes, follow the current edition of the National Fuel Gas Code:

ANSI Z223.1/NFPA 54 in the USA or B149.1 Natural Gas and Propane Installation code in Canada.

2. Properly ground the unit in accordance with all local codes, or in the absence of local codes, with the current

edition of the National Electrical Code: ANSI/NFPA 70 in the USA or CSA standard C22.1 Canadian Electrical

Code Part 1 in Canada.

3. Carefully plan where you intend to install the water heater. Please ensure:

• Your water heater will have enough combustion air and proper ventilation.

• Locate your heater where water leakage will not damage surrounding areas. (Please refer to p. 8.)

4. Check the rating plate for the correct GAS TYPE, GAS PRESSURE, WATER PRESSURE and ELECTRIC RATING. If

this unit does not match your requirements, do not install and consult with the manufacturer. The water

heater is configured only for use with Natural Gas at the factory. If the appliance is used with propane gas,

conversion to propane gas with an included conversion kit (LP Conversion Kit: 100270585) is required. The

conversion must be done by a qualified service agent or a gas utility service person in accordance with this

instruction and all codes and requirements of the authority having jurisdiction. Failure to follow instructions

could result in property damage, serious personal injury, or death. The agent performing this work assumes

responsibility for this conversion. (Refer to the gas conversion leaflet.)

5. If any problem should occur, turn off all hot water fixtures and turn off the gas. Then call a trained technician,

the gas company, or the manufacturer.

Safety Guidelines

Installaon Manual

WARNING

• Water temperatures over 125 °F (52 °C) can cause severe burns instantly or death from

scalding. The water temperature is set at 120 °F (50 °C) from the factory to minimize any

scalding risk. Before bathing or showering, always check the water temperature.

• Do not store or use gasoline or other flammables, vapors, or liquids in the vicinity of this appliance.

• Do not reverse the water and/or gas connections as this will damage the gas valves and can

cause severe injury or death. Follow the diagram on p. 28 when installing your water heater.

• The conversion to propane must be done by a qualified service agent or a gas utility

serviceman in accordance with the gas conversion instructions and all codes and

requirements of the authority having jurisdiction. Failure to follow instructions could

result in serious injury or property damage. The qualified agent performing this work

assumes responsibility for this conversion.

• Do not use this appliance if any part has been under water. Immediately contact a

qualified installer or service agency to replace a flooded water heater. Do not attempt

to repair the unit! It must be replaced!

• Do not disconnect the electrical supply if the ambient temperature will drop below

freezing. The Freeze Protection System only works if the unit has electrical power. The

warranty will not be covered if the heat exchanger is damaged due to freezing. For more

information, refer to Freeze Protection System on p. 45.

• Failure to observe these warnings can result in serious personal injury or death.

7 Page

INSTALLATION

GENERAL

1. Follow all local codes, or in the absence of local codes, follow the current edition of the National Fuel

Gas Code: ANSI Z223.1/NFPA 54 in the USA or B149.1 Natural Gas and Propane Installation Code in

Canada.

2. All gas water heaters require careful and correct installation to ensure safe and efficient operation.

This manual must be followed exactly. Read the “Safety Guidelines” section.

3. The manifold gas pressure is preset at the factory. It is computer controlled and should not need

adjustment.

4. Maintain proper space for servicing. Install the unit so that it can be connected or removed easily.

Refer to the "Clearances" section on p. 9 for proper clearances.

5. The water heater must be installed in a location where the proper amount of combustible air will be

available to it at all times without obstructions.

6. Electrical service to the water heater requires a means of disconnection. This will allow power to the

water heater to be shut off for servicing and safety purposes.

7. Do not install the unit where the exhaust vent is pointing into any opening in a building or where the

noise may disturb your neighbors. Ensure that the vent termination meets the minimum distance

requirements set by code, including minimum clearances from doorways or openings. (Refer to pp.23

to 25.)

8. Carefully plan the installation location of the heater and vent terminations. Contaminants such as

aerosols, lint, and fine powders (including flour) can clog the air intake and reduce the operation of the

fan. This, in turn, can cause improper combustion and reduce the life of the water heater. Regularly

ensure that the area around the water heater, vent termination, and air intake is free of dust, debris,

and other contaminants. In environments with a high level of contaminants (laundry facilities, hair

salons, pet salons, chemical plants, commercial kitchens, etc.), direct venting is required.

9. For 110U Indoor, 310U Indoor, and 510U Indoor models:

• If the water heater is used as a direct-vent appliance, the unit requires a 3 in. (76 mm)

combustible air supply pipe. The intake pipe must be sealed airtight. Refer to "VENTING

INSTRUCTIONS" on p.13 for more detail.

• Terminating the venting through a sidewall is recommended for the direct-vent system.

• Running the exhaust vent and the intake pipe parallel is recommended.

• Terminating the exhaust and intake on the same wall/surface is recommended. Terminating in

the same pressure zone allows for pressure balancing, which prevents nuisance shutdowns.

• Only install the water heater in a heated area where below freezing temperatures cannot occur.

The warranty does not cover damage caused by freezing.

• The water heater must be securely mounted to a wall or other suitable structure.

10. The 110U Outdoor, 310U Outdoor, and 510U Outdoor models are only to be installed outdoors and

only in an area with mild, temperate climates. The Outdoor model shall be wall mounted, mounted

on a stand, or installed in an approved recess box. Locate the Outdoor model in a open, unroofed area

and maintain the minimum clearances. (Refer to p.11.)

Installaon

Installaon Manual

8 Page

• Installation and service must be performed by a qualified installer (for example,

a licensed plumber or gas fitter). Otherwise, the warranty will be void.

• The installer (licensed professional) is responsible for the correct installation of

the water heater and for compliance with all national, state / provincial, and local

codes.

• The manufacturer does not recommend installing the water heater in a pit or

location where gas and water can accumulate.

• Do not have the vent terminal pointing toward any operating window, door, or

opening into a building.

• Do not install next to any source of airborne debris, such as a clothes dryer, that

can cause debris to be trapped inside the combustion chamber, unless the system

is direct-vented.

• The manufacturer does not suggest installing the water heater in an attic due to

safety issues. If you install the water heater in an attic:

• Make sure the unit will have enough combustion air and proper ventilation.

• Keep the area around the water heater and its termination clean. When dust

collects on the flame sensor, the water heater will shut down and produce an

error code.

• Place the unit where it will allow easy access for service and maintenance.

• A drain pan, or other means of protection against water damage, is

recommended to be installed under the water heater in case of leaks. The

manufacturer is not responsible for damage due to water leaks.

WARNING

• The warranty will not cover damage caused by water quality.

• Only potable water can be used with this water heater. Do not introduce pool

or spa water, or any chemically treated water into the water heater.

• Water hardness levels must not exceed 7 grains per gallon (120 ppm) for

single family domestic applications or more than 4 grains per gallon (70 ppm)

for all other types of applications. Water hardness leads to scale formation

and may affect / damage the water heater. Hard water scaling must be

avoided or controlled by proper water treatment.

• Water pH levels must be between 6.5 and 8.5.

• Well water must be treated.

• Do not install the unit where water, debris, or flammable vapors may get into the

flue terminal.

• The manufacturer recommends direct venting when the water heater is installed

in beauty salons, dry cleaners or any other locations in which such chemicals

are present in the air. Some chemicals used in beauty salons or dry cleaners may

affect the flame sensor. In such cases, the water heater may not work properly.

• Although the water heater is designed to operate with minimal sound, the

manufacturer does not recommend installing the unit on a wall adjacent to a

bedroom, or a room that is intended for quiet study or meditation, etc.

• Locate your heater close to a drain where water leakage will not do damage to

surrounding areas. As with any water heating appliance, the potential for leakage

at some time in the life of the product does exist. The manufacturer will not be

responsible for any water damage that may occur. If you install a drain pan under

the unit, ensure that it will not restrict the combustion air flow.

CAUTION

Installaon

Installaon Manual

9 Page

Top

Back

Boom

Side

Front

CLEARANCES

OPTIONAL ITEMS

Model

110U

Indoor

110U

Outdoor

310U

Indoor

310U

Outdoor

510U

Indoor

510U

Outdoor

4” Backflow preventer and F-F adaptor

✓ ✓ ✓

4" Universal Appliance Adaptor, F-F adaptor,

backflow preventer, condensate drain trap

✓ ✓ ✓

Pipe cover

✓ ✓ ✓ ✓ ✓ ✓

Recess box (Retrofit)

✓ ✓ ✓

Recess box (New construction)

✓ ✓ ✓

Sidewall vent terminator (Hood) and

Wall thimble

✓ ✓ ✓

Sidewall vent terminator (Round) and

Wall thimble

✓ ✓ ✓

Direct-vent concentric

termination

✓ ✓ ✓

6. Remote controller

✓

Included

✓

Included

✓

Included

Installaon

Installaon Manual

INCLUDED ACCESSORIES

Installation

manual

and Owner’s

guide

Temperature remote

controller kit

(Outdoor model only)

Communication cable

510U

only

LP Conversion Kit (100270585)

Qty: 1

100209924

(TM-RE42)

Qty: 1

Manifold aachments : 2 Small / 1 Large

Manifold gasket (100281157): 1

Gas conversion scker : 1

Gas conversion instrucon : 1

Spare Screw : 2

(100281157)

(100076516)

Model Top Bottom Front Back Sides

110U Indoor*

310U Indoor*

510U Indoor*

12 in.

(305 mm)

12 in.

(305 mm)

4 in.**

(102 mm)

1.0 in.

(25 mm)

3 in.

(76 mm)

110U Outdoor***

310U Outdoor***

510U Outdoor***

36 in.

(914 mm)

12 in.

(305 mm)

24 in.

(610 mm)

1.0 in.

(25 mm)

3 in.

(76 mm)

*Standard indoor installations and direct-vent indoor installations have the same clearances.

**24 inches recommended for maintenance.

***For the multiple installation of outdoor models, refer to the above clearances.

Maintain all clearances around the water

heater. Failure to do so could create a fire

hazard, potentially leading to death, serious

injury, and/or property damage.

WARNING

10 Page

The pipe cover protects

the plumbing pipes to

the water heater. It is

fixed to the bottom of

the water heater, so it

hides the plumbing and

improves the appearance

of the installation.

3. Recess box: It allows for “clean” installations. The water heater fits inside

the recess box, which hides and protects the whole water heater and plumbing.

The recess box will fit between most wall studs.

1. 4” Backflow preventer and Female-female adaptor

100112416

100112585

100266730

It prevents the backflow of air through the exhaust vent. This

helps prevent harmful exhaust gases from entering the home, as

well as helping to prevent the unit from freezing in areas where

cold air can be blown or drawn into the exhaust system.

Install this adaptor in accordance with the installation instructions

that are packaged with the adaptor and any applicable codes.

100112416 (4” Backflow preventer and F-F adaptor): Must be installed in the vertical position.

100112585 (4" Universal Appliance Adaptor, F-F adaptor, backflow preventer, condensate drain trap): Must be installed in the

vertical position on the heater's flue collar.

4. Sidewall vent terminator (Hood) and Wall thimble:

Sidewall vent termination (Round) and Wall thimble:

This component is used to terminate direct-vent (sealed

combustion) systems with indoor models that require a

3 in. intake and a 4 in. exhaust. This concentric termination provides the convenience

of only having to make one penetration through a sidewall instead of two separate

penetrations for the intake and exhaust piping. The termination includes a bird

screen, restricting small animals, pests, and foreign objects from entering into the

vent system. This sidewall termination is available in two different sizes to cover a

wide range of wall thicknesses. (Refer to the venting manufacturer's specifications

for details.)

Installaon

Installaon Manual

Covering wall thicknesses Part#

Terminator Hood 100112419

Wall Thimble 4 - 7 in. 100112732

Wall Thimble 5 - 10 in. 100112733

Termination + Thimble 4 - 7 in. 100112424

Termination + Thimble 5 - 10 in. 100112425

Covering wall thicknesses Part#

Termination 100187853

Wall Thimble 100187852

Termination + Thimble 100187154

2. Pipe cover: 100112187 (TK-PC01)

Covering wall thicknesses Part#

5.0 – 10.0 in. 100112550

12.0 – 18.0 in. 100112551

5. Direct-vent concentric termination:

The terminator hood and wall thimble can be used to vent through a wall. These terminations are special stainless steel

vents for gas appliances and are listed as Category II, III and IV. For different wall thicknesses, there are two ranges of lengths

available. (Refer to the NovaVent brochure for details.) Install these vent terminations in accordance with their installation

instructions and any applicable local codes.

Refer to p. 21 regarding the DIP switch settings for the termination.

Wall Thimble

Terminator Hood

6. Remote controller:

100209924 (TM-RE42)

100187154 (Termination + Thimble)

Outdoor recess box

for retrofic applications-

no flange

Outdoor recess box

for new construction

applications-with flange

100187853

(Termination)

100187852

(Wall Thimble)

100266729

11 Page

WARNING FOR INSTALLATIONS

FOR YOUR SAFETY, READ BEFORE INSTALLATION:

Do not install the heater where water, debris or

flammable vapors may get into the flue terminal.

This may cause damage to the heater and void the

warranty.

Do not have the vent terminal pointing toward

any opening into a building. Do not locate your

water heater in a pit or location where gas and

water can accumulate.

Do not install this water heater under an

overhang less than 3 ft (914 mm) from its top

or eaves. The area under an overhang must be

open to three sides (Outdoor models only).

Do not install next to a dryer or any source

of airborne debris that can be trapped inside

the combustion chamber, unless the system

is direct-vented. The air intake must maintain

a safe distance from the dryer's exhaust vent.

This will help to prevent lint from being drawn

into the water heater's air intake.

Prohibited

3 ft

(914 mm)

Installaon

Installaon Manual

Water heater vent terminator must be at least 2

ft (610 mm) away from an inside corner for both

outdoor installation, indoor single vent, or direct-

vent installation.

Inside

Corner

2 ft

(610 mm)

USA: 1  (30 cm) min.

Canada: 3  (91 cm) min.

USA: 1  (30 cm) min.

Canada: 3  (91 cm) min.

USA: 1  (30 cm) min.

Canada: 3  (91 cm) min.

USA: 12 in. (30 cm) above grade and

above ancipated snow level

Canada: 12 in. (30 cm) above grade

Ancipated snow level

Ensure that you meet the minimum clearances

shown below for a direct vent termination:

12 Page

Bank of DIP switches

110U and 310U

Computer board

NOTE: The dark squares indicate the correct DIP switch positions.

Lower bank of DIP switches

510U

Computer board

Installaon

Installaon Manual

Indoor models

0 to 2,000 ft

(0 to 610 m)

(DEFAULT)

2,001 to

3,000 ft

(611 to 914 m)

3,001 to

5,000 ft

(915 to 1,524 m)

5,001 to

7,500 ft

(1,525 to 2,286 m)

7,501 to

10,100 ft

(2,287 to 3,078 m)

110U and 310U models

OFF

1 2 3 4 5 6 7 8 9 10

No. 3 : OFF

No. 4 : OFF

No. 5 : OFF

OFF

1 2 3 4 5 6 7 8 9 10

No. 3 : OFF

No. 4 : ON

No. 5 : OFF

OFF

1 2 3 4 5 6 7 8 9 10

No. 3 : OFF

No. 4 : OFF

No. 5 : ON

OFF

1 2 3 4 5 6 7 8 9 10

No. 3 : OFF

No. 4 : ON

No. 5 : ON

OFF

1 2 3 4 5 6 7 8 9 10

No. 3 : ON

No. 4 : ON

No. 5 : ON

510U model

(Lower bank of

DIP switches)

OFF

1 2 3 4 5 6

No. 2 : OFF

No. 3 : OFF

No. 4 : OFF

OFF

1 2 3 4 5 6

No. 2 : OFF

No. 3 : ON

No. 4 : OFF

OFF

1 2 3 4 5 6

No. 2 : OFF

No. 3 : OFF

No. 4 : ON

OFF

1 2 3 4 5 6

No. 2 : OFF

No. 3 : ON

No. 4 : ON

OFF

1 2 3 4 5 6

No. 2 : ON

No. 3 : ON

No. 4 : ON

Altitude

DIP switches

Installation altitude

The maximum certified or

allowable installed altitude

is 10,100 ft (3,078 m) for

indoor models and 6,000

ft (1,829 m) for outdoor

models.

Outdoor models

0 to 2,000 ft

(0 to 610 m)

(DEFAULT)

2,001 to

4,000 ft

(611 to 1,219 m)

4,001 to

6,000 ft

(1,220 to 1,829 m)

110U and 310U models

OFF

1 2 3 4 5 6 7 8 9 10

No. 3 : OFF

No. 4 : OFF

No. 5 : OFF

OFF

1 2 3 4 5 6 7 8 9 10

No. 3 : OFF

No. 4 : OFF

No. 5 : ON

OFF

1 2 3 4 5 6 7 8 9 10

No. 3 : ON

No. 4 : OFF

No. 5 : ON

510U model

(Lower bank of

DIP switches)

OFF

1 2 3 4 5 6

No. 2 : OFF

No. 3 : OFF

No. 4 : OFF

OFF

1 2 3 4 5 6

No. 2 : OFF

No. 3 : OFF

No. 4 : ON

OFF

1 2 3 4 5 6

No. 2 : ON

No. 3 : OFF

No. 4 : ON

Altitude

DIP switches

HIGH-ALTITUDE INSTALLATIONS

Check the elevation where your water heater is installed. Set your DIP switches according to altitude as

shown below.

WARNING

• Adjust the appropriate DIP switches according to model and elevation as

shown below. DO NOT adjust the other DIP switches.

• Turn off the power supply to the water heater before changing the DIP

switch settings.

• Failure to observe these warnings could lead to carbon monoxide poisoning

or death.

13 Page

VENTING INSTRUCTIONS

For indoor models

-General-

WARNING

• Improper venting of this appliance can result in excessive levels of carbon

monoxide which can result in severe personal injury or death.

• Improper installation can cause nausea or asphyxiation, severe injury or death

from carbon monoxide and flue gases poisoning. Improper installation will void

product warranty.

• When installing the vent system, all applicable national and local codes must be

followed. If you install thimbles, fire stops or other protective devices and they

penetrate any combustible or noncombustible construction, be sure to follow

all applicable national and local codes.

The water heater must be vented in accordance with “Venting of Equipment" in the current edition of the

National Fuel Gas Code: ANSI Z223.1/NFPA 54, as well as applicable local building codes.

The manufacturer recommends NovaVENT™ or Z-Vent® category III, single wall, stainless steel venting.

See "Approved Category III, Single Wall, Stainless Steel Venting Suppliers and Part Numbers" on page 14.

General rules for air intake:

The water heater can obtain its combustion air from the space that it is installed in or it can be direct

vented.

• The air intake can use 3" PVC (solid core), CPVC (solid core), ABS, or category III vent.

• Use of cellular core PVC (ASTM F891), cellular core CPVC, or Radel® (polyphenylsulfone) in non-

metallic venting systems is prohibited. Covering non-metallic vent pipe and fittings with thermal

insulation is prohibited.

• Ensure that the installation location has sufficient, clean combustion air. If unsure, direct vent the

heater or refer to the Combustion Air Supply section below.

Direct venting installation:

• The maximum length of intake air piping must not exceed 60 ft (18.3 m). Deduct 5 ft (1.5 m) for

each 90° elbow or 2.5 ft (0.76 m) for each 45° elbow used in the venting system. Two 45° elbows

when connected together are equivalent to one 90° elbow. Refer to the tables on p. 19.

• When the horizontal air intake exceeds more then 5 ft, support the pipe every 3 ft with pipe hang-

ers.

• Vertical air intake pipe must be supported with pipe hangers. Ensure that the weight of the pipe

is not carried by the water heater.

Combustion air from the room:

• Install a 3" elbow into the air intake collar.

General rules for venting water heaters are:

• Place the water heater as close as possible to the vent termination.

• The vent collar of the water heater must be fastened directly to an unobstructed vent pipe.

• Do not weld the vent pipe to the water heater’s vent collar.

• Do not cut or alter the shape of the vent collar of the unit.

• The vent must be easily removable from the top of the water heater for normal service and

inspection of the unit and vent system.

• The water heater vent must not be connected to any other gas appliance or vent stack.

• Avoid using an oversized vent pipe or using extremely long runs of pipe.

• For rooftop venting, a rain cap or other form of termination that prevents rain water from

entering into the water heater must be installed.

• Do not common vent or connect any vent from other appliances to the water heater vent.

Installaon

Installaon Manual

14 Page

• A condensate collector is required for horizontal and/or vertical vent runs exceeding 5 ft of

equivalent length (not including sidewall terminatons).

• A backflow preventor should be installed in the exhaust when the heater is installed in climates

subject to freezing temperatures.

General rules for vent terminations:

• Avoid locating the water heater vent termination near any air intake devices. These fans can

pick up the exhaust flue products from the water heater and return them to the building. This

can create a health hazard.

• Locate the vent termination so that it cannot be blocked by any debris, at any time. Most codes

require that the termination must be at least 12 in. (305 mm) above grade and anticipated snow

level, but the installer may determine if it should be higher depending on the job site condition

and applicable codes.

• A proper sidewall termination is required when the water heater is vented through a sidewall.

• Refer to the following pages for exhaust termination and air inlet clearances.

Approved Category III, Single Wall, Stainless Steel Venting Suppliers and Part Numbers

WARNING! Do not mix parts or fittings of different material types, and do not mix pipe, fittings, or

joining methods from different manufacturers. Combustion exhaust can contain carbon monoxide and

must be properly vented outside. Breathing abnormal amounts of carbon monoxide can result in seri-

ous injury or death.

Description

Heater Vent Kits

Z-FLEX®

NovaVENT™ Z-VENT™

4" Straight pipe - 6" length

100112407 2NVP4.5 2SVEPWCF0406

4" Straight pipe - 12" length

100112406 2NVP41 2SVEPWCF0401

4" Straight pipe - 24" length

100112404 2NVP42 2SVEPWCF0402

4" Straight pipe - 36" length

100112403 2NVP43 2SVEPWCF0403

4" Straight pipe - 48" length

100112402 2NVP44 2SVEPWCF0404

4" Adjustable straight pipe - 10"-18" adjustability

100112405 2NVAL4 2SVSPA04

4" 45 degree elbow

100112401 2NVE445 2SVEEWCF0445

4" 90 degree elbow

100112400 2NVE490 2SVEEWCF0490

4" Sidewall termination (4"Termination Hood)

100112419 2NVHTX4 2SVSHTX04

4" Vent termination tee

100112547 2NVTT4 2SVSTTF04

4" Rain Cap

100112415 2NVRC4 2SVSRCF04

4" Extreme weather rain cap

100112548 2NVWC4 2SVSHRC04

4" Horizontal drain tee

100112414 2NVHD4 2SVEDWCF04

4" Vertical drain tee

100112413 2NVVD4 2SVEVDP04

4" wall thimble length 4"-7" wall thickness

100112732 2NVWT4 2SVSWTF04

4" wall thimble length 5"-10" wall thickness

100112733 2NVWT4L 2SVSWTEF04

4" 3-in-1 adaptor (F-F adaptor, condensate

drain, & back-flow preventer)

100112585 2NVBFA4 2SVBFDPA04

4" F-F adaptor

100112399 2NVAFF4 2SVEEWCF0445

4" Backflow preventer w/ F-F adaptor

100112416 2NVBFU4 2ZVB04

4" exhaust / 3" intake DV concentric termina-

tion - 5"-10" adjustability

100112550 2NVHTC43S 2SVSHTC43S

4" exhaust / 3" intake DV concentric termina-

tion - 12"-18" adjustability

100112551 2NVHTC43 2SVSHTC43

4" Sidewall termination, adjustable pipe

100187853 2NVBV4 n/a

4" Wall Thimble, 3"-6" wall thickness

100187852 2NVBT4 n/a

15 Page

-Combuson Air Supply-

• This gas water heater requires an adequate source of clean air for combustion

and ventilation. Without sufficient air, your water heater may not operate

properly and may emit excessive and abnormal amounts of carbon monoxide

which may result in carbon monoxide poisoning or death.

WARNING

Before installing the water heater, you must determine the amount of air needed to supply this water

heater and any other gas appliances in the same area and provide adequate air for combuson and venla-

on. Consult a qualied person if you’re unsure of the proper way to supply air to your water heater.

Before beginning

Calculate total BTU/h rang of all appliances.

To calculate the combuson air and venlaon required, add up the total BTU/h rangs of all gas burn-

ing appliances (e.g., water heaters, furnaces, clothes dryers) in the same area. Do not include appliances

that are direct vented. Refer to the following example.

Your water heater’s BTU/h rating is on the rating plate. The BTU/h ratings should be on the other

appliances’ rating plates. If you have trouble determining the BTU/h ratings, contact the manufacturer or

have a qualified person determine the ventilation requirements.

NOTICE: If you are replacing your old water heater with one that has a higher BTU/h rang, the amount of

venlaon required may be greater.

Gas Burning Appliance BTU/hRang

Gas Water Heater 140,000

Furnace 75,000

Dryer 20,000

Total 235,000

Example:

Gas Burning Appliance BTU/hRang

Gas Water Heater

Total

Your

appliances:

Does your installation space have sufficient combustion air?

Venlaon with outside air is recommended for all installaons. Even if the water heater is installed in a

large, open room inside the house, outdoor air is usually needed because modern homes are very ghtly

sealed and oen do not supply enough air to the water heater. However, when installed in a large indoor

space, it may be possible to provide enough air without outside venlaon. If you are unsure if your instal-

laon locaon has enough venlaon, contact your local gas ulity company or code ocials for a safety

inspecon or direct vent.

The following instrucons will help determine if it may be possible to install the water heater without outside

venlaon.

Check for Chemicals:

Installaons where corrosive chemicals may be present require the water heater to be direct vented. Air for

combuson and venlaon must be clean and free of corrosive or acid-forming chemicals such as sulfur, uo-

rine, and chlorine. Venlaon with outside air will reduce these chemicals, but it may not completely eliminate

them. Failure due to corrosive chemicals is not covered by the warranty. Examples of locaons that require

outside air due to chemicals include:

• Beauty salons

• Photo processing labs

• Indoor pools

• Laundry, hobby, or cra rooms

• Chemical storage areas

Products such as aerosol sprays, detergents, bleaches, cleaning solvents, gasoline, air fresheners, paint and

varnish removers, and refrigerants should not be stored or used near the water heater.

16 Page

Calculate the air volume of the room

Air requirements depend on the size of the room.

Room Volume (

) = Floor Area (

) X Ceiling Height ()

If there are large objects in the room (e.g., refrigerator, furnace, car), subtract their volume from the vol-

ume of the room to get a beer esmate of the air available.

Air Volume = Room Volume - Object Volume

NOTE: Adjoining rooms with permanently opened doorways can be counted as part of the calculaon.

Calculate required air volume

A water heater installed in an unconned ac, garage, or space requires that the space be at least 50 cubic

feet per 1,000 BTU/h of the total input for all gas burning appliances in the same area.

Required Air Volume (

) =Total Appliance Energy Rang (btu/h) X 50 

/ 1000 (btu/h)

Example:

(235,000 / 1000) x 50 = 11,750

If the air volume of the room is less than the required air volume, you must direct vent the water heater

or provide permanent outside air openings that draw in sucient air. Go to “Install with outside venla-

on” if you want to provide combuson air with outside venlaon.

If the air volume of the room is greater than the required air volume, it may be possible to install the

water heater without outside venlaon. However, be sure to consider the eects of exhaust fans.

Exhaust fans can aect the amount of combuson air that is available in your home. Appliances such

as furnaces, whole house fans, and clothes dryers draw air out of your home. If they draw air out faster

than it can be replaced, your water heater may not have enough oxygen to re properly. Back-draing

may also result, which is when negave air pressure pulls air backwards through chimneys or appliance

vents. These events can cause unsasfactory water heater performance. The best soluon is to direct

vent the water heater or install an adequate number of make-up air vents. (See “Install with outside ven-

laon.) For more informaon, consult a qualied technician or your local gas ulity.

Install with outside ventilation

Venlaon with outside air is recommended, and, for most installaons, is needed. There may be exisng

venlaon that is adequate, or you may need to add more venlaon.

Supplying outside air to the water heater typically requires two openings. One opening must be within 12

inches from the oor and the second opening must be within 12 inches from the ceiling. Although a single

opening is not preferred, you may use a single opening to outside air if the minimum free area is sized accord-

ing to Table 1. Two openings must be used when venlang with air from another room.

The outside air can be taken from a crawl space or ac open to the outdoors and adequately venlated.

You may use vercal or horizontal ducts.

Determine type of ventilation

There are several types of venlaon that can be used :

1. Direct to outdoors

2. Vercal ducts

3. Horizontal ducts

4. Single opening (not recommended; must be at least 100 square inches. Not appropriate for conned

spaces smaller than 50 cubic feet per 1,000 BTU/h or when geng air from another room.)

5. From a larger room inside the house (not recommended – refer to "Calculate the air volume of the room"

above to determine if the combined volume of the rooms may be adequate).

Determine minimum free area required for each vent opening

The size of the vent openings depends on the total BTU/h rang of all appliances in the space (use your calculaon

from “Before beginning”) and the type of vent used. Table 1 provides the minimum free area for each vent opening

depending on the type of venlaon.

17 Page

Calculate minimum size of vent openings and ducts

The vent cross-seconal area needed to provide the free area depends on the covering on the vent openings. Typical

vents use louvers or grilles to protect the opening. The louver or grill itself blocks some of the free area, so the open-

ing may need to be larger to meet the minimum free area requirements.

Use the following formula to calculate the required cross-seconal area:

Cross-seconal area = minimum free area required ÷ percent free area of covering (in decimals – e.g., 60% = 0.6)

For example, an installaon area that requires openings with 100 square inches of free area would need

134 square inch openings if using metal louvers rated at 75% free area (100 sq. in. ÷ 0.75 = 134 sq. in.).

If you do not know the % free area for your louver or grill, use the following values:

• For wood louvers or grilles: 25%

• For metal louvers or grilles: 75%

Follow these rules to ensure that vents and ducts provide adequate air ow:

• Each vent opening must be no smaller than 100 square inches .

• Ducts must have the same cross-seconal area as free area of the opening.

• Rectangular ducts must have a minimum dimension of no less than three inches .

• All screens must have mesh ¼” or larger.

• Moveable louvers must be locked open or interconnected with the equipment so that they open automa-

cally during operaon.

• Keep louvers and grills clean and free of debris or other obstrucons.

Check that air source is clean and free of chemicals

Air for combuson and venlaon must be clean and free of corrosive or ammable chemicals. A failure due to cor-

rosive chemicals in the air is not covered by the warranty. Combuson air must be free of acid-forming chemicals such

as sulfur, uorine, and chlorine. Be sure that air at the vent inlets is free of such chemicals.

See graphics on next page.

Table 1

Minimum Free Area of Permanent Openings for Venlaon and Combuson Air Supply – Air from outdoor or

indoor spaces.

Based on the total BTU/h input rang for all gas burning appliances within a conned space.

Opening Source Minimum Free Area

Direct to outdoors* 1 sq. in. per 4,000 BTU/hr (see Figure 1, 2)

Vercal ducts 1 sq. in. per 4,000 BTU/hr (see Figure 3)

Horizontal ducts 1 sq. in. per 2,000 BTU/hr (see Figure 4)

Single Opening 1 sq. in. per 3,000 BTU/hr (see Figure 5)

Two permanent openings

to another room**

1 sq. in. per 1,000 Btu/hr (see Figure 6)

Opening: 100 in.

MIN.

Minimum dimension of air openings:

no less than 3 in.

*These openings connect directly with the outdoors through a venlated ac, a venlated crawl space, or through

an outside wall.

** For direcon on combining spaces in dierent stories within the structure, refer to the current edion of the

Naonal Fuel Gas Code ANSI Z223.1/NFPA 54.

18 Page

CombusonAirSupplyOpons

Gable vent

to outdoors

Install above

insulaon

Outlet air to

ac 1 in

per

4,000 btu/h

Inlet air from

the crawl space

Open foundaon vent

Conﬁned

Space

Alternate

Air Inlet

1 in

per

4,000 btu/h

Figure 1 - Direct to outdoors openings

Figure 3 - Vercal duct openings

Outlet air to

ac 1 in

per

4,000 btu/h

Inlet air duct

1 in

per

4,000 btu/h

Conﬁned

Space

12” maximum

Gable vent

to outdoors

Install above

insulaon

Figure 5 - SIngle opening

Conﬁned

Space

1 in

per

3,000 btu/h

Alternave

Opening

Locaon

Figure 6 - Two permanent openings

Two permanent

Openings

1 in

per

1,000 btu/h

12” maximum

Conﬁned

Space

Figure 4 - Horizontal duct openings

1 in

per

2,000 btu/h

Conﬁned

Space

Outlet

Inlet

Outdoor

Air Ducts

1 in

per

2,000 btu/h

Figure 2 - Direct to outdoors openings

Two permanent openings

Two permanent

Openings

1 in

per

4,000 btu/h

12” maximum

Conﬁned

Space

19 Page

-Vent length and No. of Elbows-

The vent system must be sealed airtight. All seams and joints without gaskets must be sealed with high

heat resistant silicone sealant or UL listed aluminum adhesive tape having a minimum temperature rating

of 350 °F (177 °C). For best results, a vent system should be as short and straight as possible.

• This water heater is a Category III appliance and must be vented accordingly with any 4 in. (102

mm) vent approved for use with Category III or Special BH type gas vent.

• Follow the vent pipe manufacturer’s instructions when installing the vent pipe.

• Do not common vent this appliance with any other vented appliance. (Do not terminate vent

into a chimney. If the vent must go through the chimney, the vent must run all the way through

the chimney with Category III approved or Special BH vent pipe.)

• When the horizontal vent run exceeds 5 ft (1.5 m), support the vent run at 3 ft (0.9 m) intervals

with overhead hangers.

• The maximum length of exhaust vent piping must not exceed 60 ft (18.3 m).* Deduct 5 ft

(1.5 m) for each 90° elbow used in the venting system. Do not use more than 6 elbows. A 45°

elbow is equivalent to 2.5 ft of vent length.

*If vent termination kit 100187154 is used in the installation, the maximun length of exhaust vent pipe

must not exceed 55 ft (16.8 m) , and the vent run must not exceed 5 elbows. Vent termination kit

100187154 also has specific DIP switch settings. Refer to p. 22.

Vent type Diameter Max. No. of Elbows Max. Vertical and Horizontal (Total) Vent Length

Intake** 3 in. (76 mm) 6** 60 ft (18.3 m )*

Exhaust 4 in. (102 mm) 5 55 ft (16.8 m )*

*For each 90° elbow added, deduct 5 ft (1.5m) from max. vent length.

**For Intake vent, refer to the above table of the installation of 6 elbows and 60 ft.

Vent type Diameter Max. No. of Elbows Max. Vertical and Horizontal (Total) Vent Length

Intake 3 in. (76 mm) 6 60 ft (18.3 m )*

Exhaust 4 in. (102 mm) 6 60 ft (18.3 m )*

*For each 90° elbow added, deduct 5 ft (1.5m) from max. vent length.

No. of Elbows

Max. Vertical or Horizontal

Vent Length

No. of Elbows

Max. Vertical or Horizontal

Vent Length

0 60 ft (18.3m) 4 40 ft (12.2 m)

1 55 ft (16.8 m) 5 35 ft (10.7 m)

2 50 ft (15.2 m) 6 30 ft (9.1 m)

3 45 ft (13.7 m)

Excludes elbow termination, rain caps, or the 4 in. (102 mm) Concentric termination.

No. of Elbows

Max. Vertical or Horizontal

Vent Length

No. of Elbows

Max. Vertical or Horizontal

Vent Length

0 55 ft (16.8 m) 3 40 ft (12.2 m)

1 50 ft (15.2 m) 4 35 ft (10.7 m)

2 45 ft (13.7 m) 5 30 ft (9.1 m)

Excludes sidewall termination.

Installaon

Installaon Manual

Standard Vent Terminations (See the next table for vent termination 100187154.)

Installation with vent termination kit 100187154

20 Page

-DIP Switch Settings for Vent Length-

Single Pipe with Room-Air Intake

HorizontalInstallaon

Wall

Hanger

Sidewall vent

terminaon

Vertical

condensation

drain**

Backflow

preventer*

*Backflow preventer (Recommended for freezing weather conditions: 36 °F (2 °C) and below).

**Vertical condensation drain must be installed in accordance with local codes. It is required to be installed in the vent-

ing system when there is more than 5 ft (1.5 m) of equivalent vent length, not including the sidewall termination. 90° elbow

is equivalent to 5 ft (1.5 m) of vent length.

VercalInstallaon

Roof

ashing

Roof

Fire stop

Hanger

Vertical

condensation

drain**

Backflow

preventer*

Rain cap

110U Indoor

310U Indoor

510U Indoor

(Upper bank of DIP switches)

Vent length

No. 6 : O N

No. 7 : OFF

No. 8 : OFF

No. 3 : O N

No. 4 : OFF

No. 5 : OFF

0 to 60 ft

(0 to 18.3 m)

OFF

1 2 3 4 5 6 7 8 9 10

OFF

1 2 3 4 5 6 7 8

DIP switch settings for single pipe with room-air intake

• Improper venting of this appliance can result in excessive levels of carbon

monoxide which can result in severe personal injury or death.

• Improper installation can cause nausea or asphyxiation, severe injury

or death from carbon monoxide and flue gases poisoning. Improper

installation will void product warranty.

• Specific DIP switch settings are required depending on the length of your

vent run and the type of vent installation. Refer to the following sections

for details:

• Single Pipe with Room Air (page 20)

• Two-pipe Direct Vent (page 21)

• Vent kit of 100187154 (page 22)

• Outdoor Installation (page 22)

WARNING

21 Page

Installaon

Installaon Manual

Two-Pipe, Direct-Vent Installaon Examples

Vertical

condensation

drain**

HorizontalInstallaon

Wall

Hanger

Sidewall vent

terminaon

Backflow

preventer*

Fire stop

VercalInstallaon

Vertical

condensation drain**

Backflow

preventer*

Rain cap

Roof ashing

Hanger

Wall

Direct-vent

concentric

terminaon

HorizontalInstallaonwith

direct-ventconcentricterminaon

(Refer to p.10)

110U Indoor

310U Indoor

510U Indoor

(Upper bank of DIP switches)

Vent length

No. 6 : O N

No. 7 : OFF

No. 8 : OFF

No. 3 : O N

No. 4 : OFF

No. 5 : OFF

0 to 20 ft

(0 to 6.1 m)

No. 6 : OFF

No. 7 : OFF

No. 8 : OFF

No. 3 : OFF

No. 4 : OFF

No. 5 : OFF

21 to 40 ft

(DEFAULT)

(6.2 to 12.2 m)

No. 6 : O N

No. 7 : O N

No. 8 : OFF

No. 3 : ON

No. 4 : ON

No. 5 : OFF

41 to 60 ft

(12.3 to 18.3 m)

OFF

1 2 3 4 5 6 7 8 9 10

OFF

1 2 3 4 5 6 7 8

OFF

1 2 3 4 5 6 7 8 9 10

OFF

1 2 3 4 5 6 7 8

OFF

1 2 3 4 5 6 7 8 9 10

OFF

1 2 3 4 5 6 7 8

DIP switch settings for direct vent installation

*Backflow preventer (Recommended for freezing weather

conditions: 36 °F (2 °C) and below).

**Vertical condensation drain must be installed in accordance with

local codes. It is required to be installed in the venting system when there

is more than 5 ft (1.5 m) of equivalent vent length, not including the sidewall

termination. 90° elbow is equivalent to 5 ft (1.5 m) of vent length.

Direct-ventsidewallInstallaon

(Refer to p.23)

1 ft (305 mm)

min.

0.4 ft

(130 mm)

min.

0.4 ft

(130 mm)

min.

Exhaust

Intake

Exhaust

Intake

22 Page

Two-Pipe, Direct-vent

sidewallInstallaon

Single Pipe

with Room-Air Intake

Installaon

Installaon Manual

Horizontal Installaon with the 100187154 vent kit

Covering wall thicknesses Part#

Termination 100187853

Wall Thimble 100187852

Termination + Thimble 100187154

110U Indoor

310U Indoor

510U Indoor

(Upper bank of DIP switches)

Vent length

No. 6 : O N

No. 7 : O N

No. 8 : OFF

No. 3 : ON

No. 4 : ON

No. 5 : OFF

0 to 55 ft

(0 to 16.8 m)

OFF

1 2 3 4 5 6 7 8 9 10

OFF

1 2 3 4 5 6 7 8

For the Direct vent kit of 100187154, set the following DIP switch settings.

Outdoor Installaon DIP switch sengs

110U Outdoor

310U Outdoor

510U Outdoor

(Upper bank of DIP switches)

No. 6 : OFF

No. 7 : O N

No. 8 : OFF

No. 3 : OFF

No. 4 : O N

No. 5 : OFF

OFF

1 2 3 4 5 6 7 8 9 10

OFF

1 2 3 4 5 6 7 8

Outdoor installation

100187154 (Termination + Thimble)

100187852

(Wall Thimble)

3 - 6"

100187853

(Termination)

2 - 5"

3 - 7"

*Backflow preventer (Recommended for freezing weather conditions: 36 °F (2 °C) and below.)

**Vertical condensation drain must be installed in accordance with local codes. It is required to be installed in the vent-

ing system when there is more than 5 ft (1.5 m) of equivalent vent length, not including the sidewall termination. 90° elbow is

equivalent to 5 ft (1.5 m) of vent length.

Vertical

condensation

drain**

Vertical

condensation

drain**

Backflow

preventer*

Backflow

preventer*

23 Page

Installaon

Installaon Manual

-Clearances for sidewall terminations-

1 ft (305 mm) min.

Exhaust

Intake

0.4 ft

(130 mm)

min.

Exhaust

Intake

0.4 ft

(130 mm)

min.

1 ft (305 mm)

min.

0.4 ft

(130 mm)

min.

0.4 ft

(130 mm)

min.

Exhaust

Intake

Exhaust

Intake

For direct-vent

sidewall terminations

that use two separate

penetrations for the

intake and exhaust,

comply with the

minimum clearances

shown in the

diagrams below.

Improper installation can result in carbon monoxide poisoning or death. Follow all local

and national codes in regards to proper termination clearances. In the absence of such

codes, the clearances below must be met. Local codes supersede these clearances.

Failure to observe this warning may result in severe personal injury or death.

WARNING

Exhaust and/

or direct

vent sidewall

terminations

should be at least

2 ft (610 mm) away

from an opposite

surface/wall. Do

not place the

termination directly

in front of an opening

into a building.

Ancipated Snow level

Exhaust

Terminaon

2

(610 mm)

min.

1

(305 mm)

min.

1

(305 mm)

min.

Inside

corner

Exhaust

termination

2 ft (610 mm) min.

Inside

corner

Ancipated Snow level

2

(610 mm)

min.

1

(305 mm)

min.

1

(305 mm)

min.

Combined

intake and

exhaust

terminaon

Multiple Sidewall Terminations

An exhaust termination must be

at least 1 ft (305mm) away from

another exhaust termination. An

exhaust termination must also be

at least 2 ft (610 mm) away from

an inside corner. (If the adjacent

wall is less than 2 ft (610 mm) of

length, the minimum required

distance away from the inside

corner will be equal to the length

of that adjacent wall.)

Multiple DV Sidewall

Terminations

A direct vent (DV) termination

must be at least 1 ft (305 mm)

away from other direct vent

terminations.

A direct vent termination must

also be at least 2 ft (610 mm)

away from an inside corner. (If

the adjacent wall is less than

2 ft (610 mm) of length, the

minimum required distance

away from the inside corner will

be equal to the length of that

adjacent wall.)

Direct vent sidewall

terminations

that use two separate

penetrations for

the intake and

exhaust, distance the

intake and exhaust

terminations at

least 3 ft (915 mm)

away from each

other, no matter the

orientation.

Ancipated Snow level

3

(915 mm)

min.

3

(915 mm)

min.

1

(305 mm)

min.

Air supply

inlet

Air supply

inlet

Air supply

inlet

Exhaust

terminaon

24 Page

Installaon

Installaon Manual

-Clearances for rooop terminaons-

• Exhaust terminations must be at least 1 ft (305 mm) away from any obstructions.

• Minimum spacing between multiple terminals:

• intake terminals: 1 ft (305 mm) spacing between each

• exhaust terminals: 1 ft (305 mm) spacing between each

• The exhaust termination must be a horizontal distance of at least 2 ft (610 mm) from a

wall or surface unless specified differently by local code.

• Failure to observe this warning may result in severe personal injury or death.

WARNING

Flat roof terminationAngled roof termination

Vercal wall

1 

(305 mm)

min.

2 

(610 mm)

min.

2 

(610 mm)

min.

1 

(305 mm)

min.

1 

(305 mm)

min.

1 

(305 mm)

min.

1 

(305 mm)

min.

3  (914 mm) min.

Exhaust gas

Intake air

Ancipated snow level

1 

(305 mm)

min.

Multiple flat roof terminations

Exhaust

gas

Exhaust

gas

Intake air

1 

(305 mm)

min.

1 

(305 mm)

min.

1 

(305 mm)

min.

1 

(305 mm)

min.

Ancipated snow level

1 

(305 mm)

min.

2  (610 mm) min.

Multiple angled roof terminations

• Exhaust terminations must be at least 1 ft (305 mm) away from any obstructions.

• In lieu of using roof caps, a 90 degree elbow and 45 degree elbow can be used for the exhaust, and

two 90 degree elbows can be used for the air intake.

3 ft (914 mm) min.

1 ft

(305 mm) min.

1 ft

(305 mm) min.

Intake air

Exhaust

gas

Anticipated

snow level

2 ft (610 mm) min.

1 ft

(305 mm) min.

1 ft

(305 mm) min.

Intake air

Exhaust

gas

Anticipated

snow level

Improper installation can result in carbon monoxide poisoning or death. Follow all local

and national codes in regards to proper termination clearances. In the absence of such

codes, the clearances below must be met. Local codes supersede these clearances.

Failure to observe this warning may result in severe personal injury or death.

WARNING

25 Page

Installaon

Installaon Manual

-Vent terminaon clearances-

Operable

Fixed

closed

Fixed

closed

Operable

Inside corner

detail

= Vent terminal

= Air supply inlet

= Area where the terminal

is not permied

Regulator/Gas meter

vent outlet

Canada Installations

US Installations

Direct vent and other than

direct vent

Direct

vent

Other than

directdvent

A Clearance above grade, veranda, porch, deck, or balcony 1 ft (30 cm) 1 ft (30 cm)

B Clearance to window or door that may be opened 3 ft (91 cm)

1 ft

(30 cm)

4 ft (1.2 m) below or to

side of opening; 1 ft (30

cm) above opening

C Clearance to permanently closed window 0 0 0

Vertical clearance to ventilated soffit located above the

vent terminator within a horizontal distance of 2 feet

(61cm) from the center line of the terminator

3 ft (91 cm)

3 ft

(91 cm)

3 ft (91 cm)

E Clearance to unventilated soffit 3 ft (91 cm)

3 ft

(91 cm)

3 ft (91 cm)

F Clearance to outside corner 2 ft (61 cm)

2 ft

(61 cm)

2 ft (61 cm)

G Clearance to inside corner 2 ft (61 cm)

2 ft

(61 cm)

2 ft (61 cm)

Clearance to each side of center line extended above

meter/regulator assembly

3 ft (91 cm) * *

I Clearance to service regulator vent outlet

Above a regulator within 3

ft (91 cm) horizontally of the

vertical center line of the

regulator vent outlet to a

maximum vertical distance of

15 ft (4.5 m)

* *

Clearance to non-mechanical air supply inlet to build-

ing or the combustion air inlet to any other appliance.

3 ft (91 cm)

1 ft

(30 cm)

4 ft (1.2 m) below or to

side of opening; 1 ft (30

cm) above opening

K Clearance to mechanical air supply inlet 6 ft (183 cm)

3 ft (91 cm) above if within

10 ft (3 m) horizontally.

Clearance above paved sidewalk or paved driveway

located on public property

7 ft (213 cm)**

7 ft

(213 cm)

7 ft (213 cm)

M Clearance under veranda, porch deck, or balcony 1 ft (30 cm)***

1 ft (30

cm)***

1 ft (30 cm)***

*Clearances in accordance with local installation codes and the requirements of the gas supplier.

**A vent shall not terminate directly above a sidewalk or paved driveway that is located between two single family dwellings

and serves both dwellings.

***Permitted only if veranda, porch, deck, or balcony is fully open on a minimum of two sides beneath the floor.

Notes:

1) In accordance with the current CSA B149.1, Natural Gas and Propane Installation Code

2) In accordance with the current ANSI Z223.1/NFPA 54, National Fuel Gas Code

26 Page

GAS SUPPLY AND GAS PIPE SIZING

-General-

• Minimum and maximum inlet gas pressures:

• Inlet gas pressures that fall outside the range of values listed above may adversely affect the

performance of the water heater. These pressures are measured when the water heater is in full

operation and when it is in stanby.

• Inlet gas pressure must not exceed the above maximum values; gas pressure above the specified range

will cause dangerous operating conditions and damage to the unit.

• Until testing of the main gas line supply pressure is completed, ensure the gas line to the water heater

is disconnected to avoid any damage to the water heater.

• If the gas supply pressure to the heater is greater than the specified maximum, a field-supplied

regulator is required. The regulator must lower the gas pressure within the approved range.

• Install the gas regulator according to the manufacturer's instructions.

• The regulator must be sized for the water heater input and provide the specified pressures that

are listed on the rating plate.

• In the absence of minimum install distance, it is recommended that there is at least 3 ft (1 m) of

piping between the regulator outlet and the water heater's inlet gas connection.

-Gas connecons-

1. Install a full port, manual gas shutoff valve between the water heater and the gas supply line.

2. When the gas connections are completed, it is necessary to perform a gas leak test either by applying

soapy water to all gas fittings and observing for bubbles or by using a gas leak detection device.

• The water heater and its individual shutoff valve must be disconnected from the gas supply

piping system during any pressure testing of that system at test pressures in excess of 1/2 psi

(3.5 kPa).

• The water heater must be isolated from the gas supply piping system by closing its individual

manual shutoff valve during any pressure testing of the gas supply piping system at test

pressures equal to or less than 1/2 psi (3.5 kPa).

3. Always purge the gas line of any inert gas, debris, and/or water before connecting to the gas inlet.

Size the gas pipe to supply the necessary volume of gas for the water heater. Refer

to and follow the requirements listed in the current edition of ANSI Z223.1/NFPA

54 (USA), B149.1 (Canada), or local codes. Otherwise, flow capabilities and output

temperatures will be limited.

NOTICE

Gas type Inlet gas pressure

Natural Gas Min. 4.0” W.C. (1.00 kPa) – Max. 10.5” W.C. (2.61 kPa)

Propane Min. 8.0” W.C. (1.99 kPa) – Max. 14.0” W.C. (3.48 kPa)

• Do not use this water heater with any gas other than the one listed on the

rating plate unless the water heater has been properly converted.

• Ensure that any and all gas regulators used are operating properly and

providing gas pressures within the specified range shown below. Excess gas

inlet pressure may cause serious accidents.

• If your water heater needs a gas conversion, refer to the instructions supplied

with the water heater and included with the conversion components.

Installaon

Installaon Manual

WARNING

27 Page

Based on Energy

Content of 1,000

BTU/Cubic ft:

Divide each

appliance's BTU/h

requirement by

1,000 BTU/ft

to get

the appliance's ft

requirement.

Take into account

the distance the

appliance is from

the gas meter, then

look in the above

gas chart to properly

size the line.

For sections of the

gas line supplying gas to more than one appliance (Ex: Point A to Point B), add up the cubic ft per hour requirements

of the appliances that are being supplied by that section, and size to the farthest appliance.

For Example: The section from A to B supplies gas to the furnace, range and dryer. Adding up the BTU/h requirements

and dividing by 1,000 yields a cubic ft per hour requirement of 220 cubic ft of gas per hour. The farthest appliance

is the range, which is 50 ft (15.2 m) away from the meter. According to the chart above, the 50-ft (15.2 m) column

shows that Section A to B must be 1" in order to supply 220 cubic ft per hour.

Water

heater

199,000 BTU/h

Dryer

35,000 BTU/h

Gas meter

Furnace

120,000 BTU/h

Range

65,000 BTU/h

10' (3.1 m) Length

1/2" Pipe size

15' (4.6 m) Length

1/2" Pipe size

15' (4.6 m) Length

1" Pipe size

10' (3.1 m) Length

3/4" Pipe size

10' (3.1 m) Length

1" Pipe size

5' (1.5 m) Length

1-1/4" Pipe size

10' (3.1 m) Length

3/4" Pipe size

5' (1.5 m) Length

1-1/4" Pipe size

Gas sizing example

(Natural Gas)

Installaon

Installaon Manual

Pipe Size Length: ft (m)

Diameter:

in.

10'

(3.0)

20'

(6.1)

30'

(9.1)

40'

(12.2)

50'

(15.2)

60'

(18.3)

70'

(21.3)

80'

(24.4)

90'

(27.4)

100'

(30.5)

125'

(38.1)

150'

(45.7)

200'

(61.0)

1/2"

172 118 95 81 72 65 60 56 52 50 44 40 34

3/4"

360 247 199 170 151 137 126 117 110 104 92 83 71

1" 678 466 374 320 284 257 237 220 207 195 173 157 134

1/4"

1,309 957 768 657 583 528 486 452 424 400 355 322 275

1/2"

2,090 1,430 1,150 985 873 791 728 677 635 600 532 482 412

2" 4,020 2,760 2,220 1,900 1,680 1,520 1,400 1,300 1,220 1,160 1,020 928 794

Unit: Cubic feet per hour

-Natural Gas Supply Piping-

Maximum delivery Capacity in Cubic Feet of Gas per Hour (based on IPS Pipe carrying Natural Gas with 0.60 Specific

Gravity with a Pressure Drop of 0.5" W.C.).

Based on Energy Content of 1,000 BTU/Cubic ft: The water heater requires 140 Cubic ft/hr for the 110U,

190 Cubic ft /hr for 310U, and 199 Cubic ft/hr for the 510U model.

The following tables are from NFPA 54.

Unit: kBTU per hour

Pipe Size

Length: ft (m)

Diameter

10'

(3.0)

20'

(6.1)

30'

(9.1)

40'

(12.2)

50'

(15.2)

60'

(18.3)

70'

(21.3)

80'

(24.4)

90'

(27.4)

100'

(30.5)

125'

(38.1)

150'

(45.7)

200'

(61.0)

1/2"

268 184 148 126 112 101 93 87 82 77 68 62 53

3/4"

567 393 315 267 237 217 196 185 173 162 146 132 112

1,071 732 590 504 448 409 378 346 322 307 275 252 213

1/4"

2,205 1,496 1,212 1,039 913 834 771 724 677 630 567 511 440

1/2"

3,307 2,299 1,858 1,559 1,417 1,275 1,181 1,086 1,023 976 866 787 675

6,221 4,331 3,465 2,992 2,646 2,394 2,205 2,047 1,921 1,811 1,606 1,496 1,260

-Propane (LP) Supply Piping-

Maximum Capacity of Propane (LP) Based on 11" W.C. supply pressure at a 0.5" W.C. pressure drop

28 Page

Cold

inlet

Hot

outlet

Gas

inlet

As Close as

Possible

Pressure relief valve

Installaon

Installaon Manual

4. Before installing the water heater, flush the

water line to remove all debris, and after

installation is complete, purge the air from

the line. Failure to do so may cause damage

to the water heater.

5. There is a wire mesh filter within the cold

inlet to trap debris from entering your heater.

This will need to be cleaned periodically to

maintain optimum flow. (Refer to p. 46.)

All pipes, pipe fittings, valves and other components, including soldering materials, must be suitable for

potable water systems.

1. A manual shutoff valve must be installed on the cold water inlet to the water heater between the

main water supply line and the water heater.

2. In addition, a manual shutoff valve is also recommended on the hot water outlet of the unit.

Isolation valves are recommended as shown in the picture at right.

3. If the water heater is installed within, or subjected to, a closed

loop water system, a thermal expansion tank or a code approved

device must be installed to handle thermal expansion.

WATER CONNECTIONS

-Pressure relief valve-

The water heater has a high-temperature shutoff switch built in as a standard safety feature (called a

Hi-Limit switch). Therefore, a “pressure only” relief valve is required.

• This unit does not come with an approved pressure relief valve.

• An approved pressure relief valve must be installed on the hot water outlet.

• The pressure relief valve must conform to the current edition of ANSI Z21.22 or CAN 1-4.4 and instal-

lation must follow local codes.

• The discharge capacity must be at least 140,000 BTU/h for the 110U model, 190,000 BTU/h for the

310U model, and 199,000 BTU/h for the 510U model.

• The pressure relief valve must be rated for a maximum of 150 psi (1 MPa).

• The discharge piping for the pressure relief valve must be directed so that the hot water cannot splash

outward and cause damage or personal injury.

• Attach the discharge tube to the pressure relief valve and run the end of the tube to within 6 in.

(152 mm) from the floor. This discharge tube must allow free and complete drainage without any

restrictions.

• If the pressure relief valve installed on the water heater discharges periodically, this may be due to a

defective thermal expansion tank or defective pressure relief valve.

• The pressure relief valve must be manually operated periodically to check for correct operation. No

valve shall be placed between the relief valve and the water heater.

Do not use this appliance if any part has been under water. Immediately contact a

qualified installer or service agency to replace a flooded water heater. Do not attempt

to repair the unit! It must be replaced!

WARNING

Do not reverse the hot outlet and cold inlet connections to the water heater. This will

prevent the water heater from activating properly.

NOTICE

WARNING

Hot water could be released when the pressure relief valve is opened. This could

result in severe personal injury. Contact with discharge may cause property dam-

age and/or bodily harm. Before operating the pressure relief valve manually, check

that it will discharge in a safe place. If water does not flow freely from the end of

the discharge pipe, turn the gas supply and power OFF and call a qualified person

to determine the cause.

Refer to the pressure relief valve manufacturer's instructions for inspection and

maintenance requirements.

29 Page

ELECTRICAL CONNECTIONS

• Ensure that circuit power is turned OFF before you complete the following steps.

• Follow the electrical code requirements of the local authority having jurisdiction.

In the absence of such requirements, follow the current edition of the National

Electrical Code ANSI/NFPA 70 in the U.S. or the current edition of CSA C22.1 Canadian

Electrical Code Part 1 in Canada

• When servicing or replacing parts within the water heater, label all wires prior to dis-

connection to facilitate an easy and error-free reconnection. Wiring errors can cause

improper and dangerous operation. Verify proper operation after servicing.

• Failure to follow these instructions can result in fire, electrical shock, or death.

WARNING

All indoor models come with a power plug instead of a junction box. The following procedure is for

outdoor models only.

1. The water heater must be electrically grounded. Do not attach the ground wire to either the gas or

the water piping.

2. The water heater requires a 120 VAC, 60 Hz electrical power supply that is properly grounded.

• A proper disconnect (i.e. on/off switch, power plug, etc.) controlling the main power to the water

heater must be provided for service reasons. (Must comply with local codes.)

• Connect the power supply to the water heater exactly as shown in the wiring diagram.

3. A green screw is provided in the junction box to ground the connection.

4. Can be hardwired or wired to a plug-in.

5. The use of a surge protector is recommended in order to protect the unit from power surges.

Outdoor models only

Boom view of water heater

View of electrical

connecons of water heater

Ground

wire with

terminal

Connect

power supply

120VAC, 60Hz

Green screw

Indoor models only

Installaon

Installaon Manual

30 Page

Installaon

Installaon Manual

TEMPERATURE REMOTE CONTROLLER

-Included accessories-Outdoor models only

Take off the Back plate from the remote controller with a flat head screwdriver. (Fig. A and B)

Attach the Back plate on the wall with the two provided screws. (Fig. B)

If you use another cable, crimp the Fork terminals to the wires. (Fig. C)

Fig. B

Back plate

3-1/4 inches

Attach the screws

Cut out the partition with pliers.

(removed during later steps.)

Main body

Fig. A

Main body

Twist

Press and twist flat head

screwdriver against the cutout.

Remote controller cable

1-3/8 Inch

(35 mm)

Fig. C

1-5/8 Inch

(41 mm)

Fork

Terminals

100209924 (TM-RE42)

It is also an optional accessory as a second remote for the indoor models. Refer to pp. 9 and 10.

*The optional remote controller (sold separately) has no remote controller cable.

Verify that the items listed below are included with the remote controller.

Temperature

remote controller

Screws Fork terminals Manual

Remote controller

cable*

Qty: 1

Qty: 2

Qty: 4

Qty: 1

-Installaon-

• This remote controller is NOT waterproof.

• The water heater can only have one remote controller.

• Do not install in high temperature environments, high humidity conditions outdoors, in

direct sunlight, or within the reach of children.

• Make sure the remote controller does not come into contact with water or oil.

• Failure to observe these warnings could result in personal injury or electrical shock.

WARNING

• Do not place the remote controller cable close to other wires from other products.

• Cables used for the remote controller connection must be:

• Minimum 20 gauge wire (No polarity)

• Maximum 400 ft (122 m) long

NOTICE

• The remote control is an optional accessory that can be installed in a hall, closet, etc., to allow for

temperature adjustment without having to go to the heater.

• When installed, the remote will take priority over the built-in controller of indoor models.

31 Page

Installaon

Installaon Manual

Tighten the two "Fork terminals" beneath the two

"Remote controller terminal" screws on the back of

the main body. (Fig. D-1)

Cut out the inlet for the remote controller cable

from the bottom of the main body. (Fig. D-2)

Place the "Main body" back on the "Back plate",

with the "Remote controller cable" running out of

the bottom inlet.

Remote controller

terminals

Fig. D-1

Two fork terminals

Remote controller cable

Inlet for the remote

controller cable

Cut out

Fig. D-2

Connecting the remote controller to the water heater

1. Disconnect power supply from the water heater.

2. Take off the water heater’s front cover.

3. Locate the two terminals for the remote controller in the water heater. (Refer to the Fig. E-1 and E-2.)

4. Put the remote controller cable through the hole at the bottom of the water heater's casing from

outside.

5. Secure both terminals on the controller cable to the terminals in the cabinet as shown below.

(Secure them underneath the screw terminals. No polarity.) See Figures E-1 and E-2.

* Do NOT jump or short-circuit the wires, or the computer will be damaged.

6. Replace the water heater's front cover securely.

110U and 310U

100209924

(TM-RE42)

Front of remote

Connect other end to these terminals

Fig. E-1

100209924

(TM-RE42)

Front of remote

Connect other end to these terminals

510U

Fig. E-2

32 Page

EASY-LINK SYSTEM

510U model only

The 510U model water heaters can be connected with other allowable heaters (see the table below) with

communication cables to work as a multiple-unit manifold system.

• The built-in Easy-Link System allows up to 4 units to manifold together.

• A communication cable (gray color) comes with each 510U model.

You can manifold from 2 to 4 units without the need for a multi-unit controller. A 4-unit system has full

automatic modulation between 15,000 BTU/h and 796,000 BTU/h.

-General-

Easy-Link connection

with allowable heaters

T-K3

T-K3-Pro

510 model

510U model (AT-D2U-IN/OS)*

510U model (AT-D3U-IN/OS)*

200 series

Gas In

Hot Out

Cold In

• *If the 510U (AT-D2U-IN/OS) models and the 510U (AT-D3U-IN/OS) models are

incorporated in an Easy-Link Sytem with the other models in the table above,

change DIP switch No. 6 on the lower bank of all the 510U (AT-D2U-IN/OS) and

510U (AT-D3U-IN/OS) computer boards to the “ON” position.

• Turn off the power supply to the water heater before changing the DIP switch settings.

• The Easy-Link System is limited to up to 4 units. If you connect more than 4 units,

only the first 4 units will work as a part of the Easy-Link System. The other additional

units will not work as part of the system.

• Only listed models on the table above can be combined together as an Easy-Link

System. These models cannot be combined together with other models not listed

on the table above.

• A remote controller is not required for an Easy-Link System. However, it does provide

for more temperature options and ease of maintenance.

• If a remote controller is used, the temperature on all the units in the system will auto-

matically be set to the same temperature that is set on the remote.

• When a remote is used in an Easy-Link System, it must be connected to the parent unit.

OFF

DIP switch setting on the 510U (AT-D2U-IN/OS) and 510U (AT-D3U-IN/OS)

(Lower bank of DIP switches)

The dark square indicates the correct DIP switch position.

NOTICE

-Easy-Link Connecon Procedures-

1. Make sure the power to the heaters is turned off.

2. Verify the DIP switch set temperatures of all units within the system. Every water heater must be

set to the same set temperature. If an optional remote controller (100209924/TM-RE42) is used, it

should be installed to the “PARENT” unit. (See section B on the next page.) The remote will set the

temperature for the entire system.

3. Select one unit to be the “PARENT” unit. The “PARENT” unit should be one of the end units.

4. “PARENT” unit:

Locate the two banks of DIP switches at the bottom left of the computer board of the unit that you

select to be the “PARENT” unit. Change DIP switch No. 1 on the lower bank of DIP switches to the

ON position. See the computer board diagram as shown on the next page. Do not change any DIP

switches on any of the “CHILD” units.

5. Between the “PARENT” and the “CHILD-1” units:

Connect the “PARENT” connector of the “PARENT” unit to the “1” connector of the “CHILD-1” unit

using the supplied linking cable.

Installaon

Installaon Manual

33 Page

6. Between the “CHILD-1” and the “CHILD-2” units:

Connect the “2” connector of the “CHILD-1” unit to the “1” connector of the “CHILD-2” unit.

7. Between the “CHILD-2” and the “CHILD-3” units:

Connect the “2” connector of the “CHILD-2” unit to the “1” connector of the “CHILD-3” unit.

8. Verify that all cables are connected like the diagram (B).

9. Turn on power to the “PARENT” unit.

Next, turn on “CHILD-1”. When the controller* installed in “CHILD-1” unit displays a number, turn on

“CHILD-2”.

When the controller* installed in the “CHILD-2” unit displays a number, turn on “CHILD-3”.

Make sure the controller* installed in each child unit dis-

plays each unit number. (Refer to p. 48.) The numbering

system automatically allocates the unit number to each

water heater in the Easy-Link System, in accordance with

the table on the right.

10. Set the water temperature using the controller* installed in the “PARENT” unit. It will set the tem-

perature for the Easy-Link System. If a remote controller is installed to the “PARENT” heater of 510 U

Indoor, it will override the built-in controller.

*Built-in controller for indoor models, remote controller for outdoor models.

(A) 510U model Computer board

WARNING

• To change the DIP switch settings for the Easy-Link System, locate the

lower bank of DIP switches at the bottom, left of the computer board.

• DO NOT adjust any other DIP switches.

• Turn off the power supply to the water heater before changing the DIP

switch settings.

• Failure to observe this warning could result in carbon monoxide poison-

ing or death.

Easy-Link /

Mul-Unit

connectors

are next to

the computer

board.

Lower bank of DIP switches

Upper bank of DIP switches

(B) Basic diagram of connections between the Easy-Link System units

NOTE: The dark square indicates the correctDIPswitchposition.

PARENT

Communicaon cable

Lower bank of

DIP switches

OFF

PARENT

OFF

Lower bank of

DIP switches

Lower bank of

DIP switches

Lower bank of

DIP switches

Connectors Connectors Connectors Connectors

PARENT unit

CHILD-1 unit CHILD-3 unit

CHILD-2 unit

Remote controller

Installaon

Installaon Manual

Type of unit Unit # of easy-link

Parent 1

Child 2, 3, or 4

34 Page

Installaon

Installaon Manual

• The parent/child DIP switch, No.1 on the lower bank of DIP switches, should be in the OFF

position.

• This is the connection diagram between 510U and multi-unit controller for 2 to 20

water heaters. Above is an example showing seven water heaters.

• The multi-unit controller automatically allocates the unit number (1-20) to each water

heater that is part of the Multi-Unit System.

• In a Multi-Unit System, connect the “[1]” connector and the “[2]” connector with the

communication cable (refer to p. 9) or 18 gauge wire cables. The total cable length can

be up to 250 ft (76.2 m) long.

100112691

(TM-MC02)

510U

Cold IN

Hot Out

MULTI-UNIT SYSTEM

Multiple 510U models can be combined for a Multi-Unit System, along with the multi-unit controller

(Part 100112691 (TM-MC02)). Each multi-unit controller can control from 2 to 20 units for commercial

or residential applications. For a 20-unit system, the computer can modulate from 15,000 BTU/h to

3.98 million BTU/h.

An individual cut-off switch is recommend-

ed for each unit in a Multi-Unit System for

the purpose of maintenance.

Multi-Unit System connection diagram

Multi-unit controller and temperature remote controller wiring:

OFF

PARENT

Connectors Connectors Connectors

OFF

Lower bank of

DIP switches

Lower bank of

DIP switches

Lower bank of

DIP switches

Lower bank of

DIP switches

Lower bank of

DIP switches

Lower bank of

DIP switches

Lower bank of

DIP switches

Communicaon cable

Remote controller cable

PARENT

Connectors Connectors

OFF

PARENT

Connectors Connectors

OFF

Remote controller

100112691

(TM-MC02)

Terminals for

water heaters

Remote

controller

terminals

Example : 510U x 7 units

• For detailed instructions on the multi-unit controller, refer to the instructions

that are packaged with the multi-unit controller.

• The multi-unit controller allocates random numbering. See the controller

instructions to learn how to renumber the system units sequentially.

NOTICE

35 Page

APPLICATIONS

SPACE-HEATING APPLICATIONS

RECIRCULATION

*The recirculation pump is to be controlled by:

-Dual-set aquastat (recommended w/timer)

• The aquastat's differential should be a minimum of 10 °F (5 °C).

*The recirculation pump is to provide no less than 2 GPM (7.5 L/min) and no more than 4 GPM (15 L/min) through

each activated unit in the system. Refer to the heaters specification sheet on the manufacturer's website for

pressure drop information.

• This water heater is suitable for combination water (potable) heating and space

heating and not suitable for space heating applications only.

• In order to purge air in water pipes within a closed-loop system, an air vent and

air separator should be installed in the system. Required circulation flow rates are

labeled next to each application diagram. These flow rate requirements must be

followed.

• Toxic chemicals used in boiler treatments such as alcohol, glycerol and glycol groups

must not be introduced into the system.

• The water heater can be used to supply combination potable water and space

heating and shall not be connected to any heating system or component(s)

previously used with non-potable water where any chemicals were added to the

water heating appliances.

• When the system requires water for space heating at temperatures higher than

required for other uses, a means such as a mixing valve shall be installed to temper

the water for those other uses in order to reduce scald hazard potential.

• Water temperature over 125 °F (52 °C) can cause severe burns instantly or death

from scalding.

WARNING

Air vent

Hot water outlet to xtures

Recirculaon

pump

Air

separator

Check valve

Y-Strainer

Cold water inlet

Expansion tank

Gas supply

Ball valves

Unions

Hot water outlet

Cold water inlet

Gas inlet

Pressure

relief valve

This is a concept drawing only.

Applicaons

36 Page

• Priority Control Devices such as a flow switch, an Aquastat or other

electronic controller can be used to prioritize the domestic water system over

the heating system.

• Follow all local codes, or in the absence of local codes, follow the current

edition of the National Standard Code, ANSI Z21.10.3 ・ CSA 4.3.

• This illustration is a concept design only. The reference to the 1/8-inch hole

in the check valve is only required in the State of Massachusetts. There are

a wide variety of variations to the application of controls and equipment

presented. Designers must add all necessary safety and auxiliary equipment

to conform to code requirements and design practice. For more details,

contact the manufacturer or local code authority.

NOTICE

DUAL-PURPOSE HOT WATER HEATING

(Domestic and Space Heating):

Diagrammatic layout of radiant heating and domestic water heater.

The recirculation pump is to provide no less than 2 GPM (7.5 L/min) and no more than 4 GPM (15 L/min)

through each activated unit in the system

Installaon

Installaon Manual

Ball

Valve

Isolation

Valve

120 VAC

switch or

outlet

Hot water outlet

Unions

T-handle gas shuto valve

Check valve

Electronically controlled

pump mer. Acvates

every 6 hours for 60

seconds. Wire to

product approved pump

HeangCoil

(used with air-handler)

Cold water supply

3" intake and 4" vent

(Discharge must

comply with local and

state codes.) Cannot

be common vented

with other appliances

An approved temperature and pressure

relief valve. Tie to locaon approved by

local codes and must meet BTU rang of

water heater model used

Check valve will have

1/8-inch hole drilling

in clapper.

Atmospheric

vacuum

breaker

Shuto

valve

Pressure

gauge

Apply correct thermal

expansion tank-size

per applicaon

Shuto valves

Check valves

Cold water inlet

Gas inlet

Water

lter

Drain

plug

Thermostac mixing valve

Hot water

supply and

return to

heang coil

System installed with reverse

acng aquastat to shut o fan.

Suggested but not required by

248 CMR

50’-0” MAXIMUM DISTANCE FROM

WATER HEATER TO FAN COIL AND

BACK (DEVELOPED LENGTH) NOT

INCLUDING COIL IN HEATING UNIT.

NSF-61 product

approved pump

Automac tempering device

must be installed below

the top of the water heater

as per manufacturer’s

recommendaons

Piping loop

between water

heater and fan

coil shall be in

compliance with

248 CMR

Tempered water to

plumbing xtures. Must

meet temperature

requirements of 248 CMR

All water piping should be insulated

in accordance with 780 CMR

(Massachuses energy code)

Water heater

accepted by

the Board for

installation in

Massachusetts.

37 Page

INITIAL OPERATION

Operation

Once the above checks have been completed, please clean the filter

of any debris. Refer to p. 46 for instructions.

Fully open the manual water control valve on the water supply line.

Open a hot water tap to verify that water is flowing to that tap, then

close the hot water tap.

Fully open the manual gas control valve.

Turn on the 120 VAC, 60 Hz power supply to the water heater.

Now you are ready to enjoy hours of endless hot water.

• Check the GAS and WATER CONNECTIONS for leaks before firing the unit for the first time.

• Open the main gas supply valve to the unit using only your hand to avoid any spark. Never use

tools. If the knob will not turn by hand, do not try to force it; call a qualified service technician.

Forced repair may result in a fire or explosion due to gas leaks.

• Be sure to check for the presence of leaking gas toward the bottom of the unit because some

gases are heavier than air and may settle toward the floor.

• Check the GAS PRESSURE. Refer to pp. 26 and 46.

• Do not try to light the burner manually. It is equipped with an electronic ignition device which

automatically lights the burner.

• Check for PROPER VENTING and COMBUSTIBLE AIR to the water heater.

• Purge the GAS and WATER LINES to remove any air pockets.

• Do not use this water heater if any part has been submersed under water. Do not attempt to

repair the unit. It must be replaced. Failure to follow these instructions could lead to property

damage, personal injury, or loss of life.

FOR YOUR SAFETY, READ BEFORE OPERATING

Inial operaon

Installaon Manual

IF YOU SMELL GAS:

• Do not try to start the water heater.

• Do not touch any electric switches; do not use any phone in your building.

• Immediately call your gas supplier from a neighbor’s phone. Follow the gas

supplier’s instructions.

• If you cannot reach your gas supplier, call the fire department.

WARNING

38 Page

Owner's Guide

CONGRATULATIONS

Congratulations and thank you for choosing our tankless water heater.

Before use, we recommend that you read through this owner's guide

carefully. Keep this manual for future reference.

If you need an additional manual, contact the manufacturer or your

local distributor. When you call, please tell us the product name and

the serial number of your unit written on the rating plate of the water

heater.

Owner's Guide

39 Page

OPERATING SAFETY

Operang Safety

Owner's Guide

WARNING:

If you do not follow these instructions exactly, a re or explosion may result

causing property damage, personal injury or loss of life.

A.Thisappliancedoesnothaveapilot.Itisequippedwithanignitiondevicewhichautomatically

lightstheburner.Donottrytolighttheburnerbyhand.

B.BEFOREOPERATINGsmellallaroundtheapplianceareaforgas.Besuretosmellnextto

theoorbecausesomegasisheavierthanairandwillsettleontheoor.

WHATTODOIFYOUSMELLGAS

• Donottrytolightanyappliance.

• Donottouchanyelectricswitch;donotuseanyphoneinyourbuilding.

• Immediatelycallyourgassupplierfromaneighbor’sphone.Followthegassupplier’s

instructions.

• Ifyoucannotreachyourgassupplier,calltheredepartment.

C.Useonlyyourhandtoturnthegasshutoffvalve.Neverusetools.Ifthevalvewillnotturnby

hand,don’ttrytorepairit,callaqualiedservicetechnician.Forceorattemptedrepairmayresult

inareorexplosion.

D.Donotusethisapplianceifanyparthasbeenunderwater.Immediatelycontactaqualied

installerorserviceagencytoreplaceaoodedwaterheater.Donotattempttorepairtheunit!It

mustbereplaced!

1. STOP!Readthesafetyinformationaboveonthislabel.

2. Turnoffallelectricpowertotheappliance.

3. Donotattempttolighttheburnerbyhand.

4. Turnthegasshutoffvalvelocatedontheoutsideoftheunittotheclosedposition.

5. Waitve(5)minutestoclearoutanygas.Ifyouthensmellgas,STOP!Follow “B”inthe

safetyinformationaboveonthislabel.Ifyoudon’tsmellgas,gotothenextstep.

6. Turnthegasshutoffvalvelocatedontheoutsideoftheunittotheopenposition.

7. Turnonallelectricalpowertotheappliance.

8. Iftheappliancewillnotoperate,followtheinstructionsin“ToTurnOffGastoAppliance,”and

callyourservicetechnicianorgassupplier.

1. Turnoffallelectricpowertotheapplianceifserviceistobeperformed.

2. Turnthegasshutoffvalvelocatedontheoutsideoftheunittotheclosedposition.

FOR YOUR SAFETY READ BEFORE OPERATING

OPERATING INSTRUCTIONS

TO TURN OFF GAS TO APPLIANCE

40 Page

Operang Safety

Owner's Guide

Apressurereliefvalvelistedascomplyingwiththestandard forReliefValve andAutomaticGasShutoff

DevicesforHotWaterSupplySystem,ANSIZ21.22

・

CSA4.4,shallbeinstalledatthetimeofinstallation

ofthewaterheaterinthelocationspeciedbythemanufacturer.Localcodesshallgoverntheinstallationof

reliefdevicesforsafetyoperationofthewaterheater.Thereliefvalvemustnotberemovedorplugged.

Novalveshallbe placed betweenthe relief valve and thewaterheater.Therelieffromthedischargeof

thepressurereliefvalveshallbedisposedofinasuitableplacewhereitwillcausenodamage.Also,there

shallbenootherreducingcouplingorotherrestrictionsinstalledonthedischargelinetorestrictow.

SeeInstallationManualheading“PRESSURERELIEFVALVES”forinstallationandmaintenanceofrelief

valvedischargelineandothersafetyprecautions.

Vapors from ammable liquids will explode and catch re causing death or severe burns.

Donotuseorstoreammableproductssuchasgasoline,solventsoradhesivesinthesameroomor

areanearthewaterheater.

Keepammableproducts:

1. Farawayfromheater.

2. Inapprovedcontainers.

3. Tightlyclosedandoutofreachofchildren.

4. Waterheaterhasamainburner,whichmay

comeonatanytimeandwilligniteammable

vapors.

Vapors:

1. Cannotbeseen.

2. Areheavierthanair.

3. Goalongwayontheoor.

4. Canbecarriedfromotherroomstothemain

burnerbyaircurrents.

Donotinstallwaterheaterwhereammableproductswillbestoredor

usedunlessthemainburnerisatleast18”abovetheoor.This

willreduce,butnoteliminatetheriskofvaporsbeingignitedbythe

mainburner.

Read and follow water heater warnings and instructions. If the owner’s

manual is missing, contact the retailer or manufacturer.

FlammableVapors

FLAMMABLES

1. Watertemperatureover125°F(52°C)cancausesevereburnsinstantlyordeathfrom

scalds.

2. Children,disabledandelderlyareathighestriskofbeingscalded.

3. Feelwaterbeforebathingorshowering.

4. Temperaturelimitingvalvesareavailable.Seemanual.

5. Theoutlettemperatureofthewaterheaterissetat120°F(50°C).If yourequirewatertemperatures

belowthissetting,followtheinstructionmanual.

6. Usethisheateratyourownrisk.Testthewaterbeforebathingorshowering.Donotleavechildrenor

aninrmpersonunsupervised.Seeyourlocalwatersupplycompany[plumbinghardwareretailer]for

temperaturelimitingvalvesthatareavailable.

BRÛLURE

BURN

CHAUDECHAUDE

HOTHOT

CHAUDE

HOT

DANGER

41 Page

Normal Operaon

Owner's Guide

NORMAL OPERATION

BUILT-IN CONTROLLER AND REMOTE CONTROLLER

The illustraon below shows an example of the controllers. The exact display may dier from examples.

"COLD" Button

"HOT" Button

Press the "HOT" button or the "COLD"

button to set the hot water temperature.

STAND BY LED (Orange)

The indicator is ON to show that

power is ON.

IN USE LED (Green)

The indicator lights during combustion.

"INFO" Button

Each time the button is pressed,

the operation mode is selected

in the sequence of the following.

Inlet water

temperature

Outlet water

temperature

Water

flow

When the STAND BY LED is ON, the

hot water temperature will be

displayed.

Display for Temperature

"ON/OFF" Button

Press this button to

start or stop operation.

Built-in controller

Remote controller

• When the remote controller is installed, it will take priority over the built-in controller.

• The controller has an energy saving mode. Five minutes after the water heater stops

operating, the backlight of the controller turns off.

• The backlight of the remote will turn back on once the water heater begins firing again.

NOTICE

GENERAL

1. Open a cold water

fixture.

2. Mix hot water with the cold water

to get the correct temperature water.

3. When finished, close the

water fixtures.

• Flow rate to activate the water heater: 0.5 gallon per minute at the default set

temperature (1.9 L/min).

• Flow rate to keep the water heater running: 0.4 gallon per minute (1.5 L/min).

NOTICE

Temperatures above 125 °F (52 °C) can cause severe burns or death from scalding.

Children, disabled and the elderly are at high risk of being injured.

WARNING

°F 120 125 130 135 140 145 150 155

°C 49 52 54 57 60 63 66 68

Time to produce

serious burn

than 5

min.

1½ to 2

min.

about

30 sec.

about

10 sec.

less than

5 sec.

less than

3 sec.

about

1½ sec.

about

1 sec.

42 Page

TEMPERATURE SETTINGS

-Set temperature-

Normal Operaon

Owner's Guide

Operation

Screen on the controller

Built-in controller Remote controller

Turn on the 120 VAC power supply to the unit (the water

heater or the multi-unit controller).

Press the "ON/OFF" button on the controller in order to

turn the controller on.

When ON, the STAND BY LED is lit.

It shows the set temperature on its display as shown in

the picture on the right. (EX.: 120 °F)

Press the "HOT" button or the "COLD" button to set the

temperature setting of the unit.

Increasing temperature from 120 °F (50 °C) to 125 °F (52 °C) :

1. The water heater must be in Stand By to increase the

temperature.

2. Press the "HOT" button to set 120 °F (50 °C).

3. Press and hold the "INFO" button and the "HOT"

button for at least 3 seconds. The remote will emit a

beep and change to 125 °F (52 °C).

4. To increase the set temperature further, press the

"HOT" button. You can increase the temperature

setting up to 140 °F (60 °C).

Increasing temperature above 140 °F (60 °C)

-510U model only-:

1. The water heater must be in Stand By to increase the

temperature.

2. Press the "HOT" button to set 140 °F (60 °C).

3. Press and hold the "INFO" button and the "HOT"

button for at least 3 seconds. The remote will emit a

beep and change to 145 °F (63 °C).

4. To increase the set temperature further, press the

"HOT" button. You can increase the temperature

setting up to 160 °F (70 °C).

(EX.: 120 °F)

°F 100 105 110 115 120* 125 130 135 140

°C 38 40 43 45 50* 52 55 57 60

a) For 110U and 310U

°F 100 105 110 115 120* 125 130 135 140 145 150 155 160

°C 38 40 43 45 50* 52 55 57 60 63 65 68 70

b) For 510U

*Factory setting (Default): 120 °F

Following are the temperature set points that are available with your built-in controller or remote

controller:

-Temperature table of controller-

43 Page

-Addional features-

Informaon mode

You can get some information about the water heater's condition by pressing the "INFO" button. For

more information, follow the procedures below:

INFO

Button

Operation

Screen on the controller

Built-in controller Remote controller

1st. press

Inlet water temperature will be displayed on

the remote controller by pressing the "INFO"

button.

Inlet water temperature

2nd. press

Outlet water temperature will be displayed on

the remote controller by pressing the "INFO"

button.

Outlet water temperature

3rd. press

Water flow will be displayed on the remote

controller by pressing the "INFO" button.

Water flow

4th. press

Press the "INFO" button to finish information

mode.

Unit conversion mode

Units of measure can be changed from Imperial to Metric and vice versa. For example, temperature can

be changed from °F to °C. Flow rate will also change from gallons per minute to liters per minute when

this setting is changed. Follow this procedure to change this setting:

Operation

Screen on the controller

Built-in controller Remote controller

Press the "ON/OFF" button on the controller in

order to turn the controller on.

When ON, the orange LED is lit.

The previous set temperature will be displayed on

the screen.

Press the "INFO" button for at least 3 seconds.

The set temperature should now be displayed in the

alternate unit of measurement.

(EX.: 100 °F)

(EX.: 38 °C)

Normal Operaon

Owner's Guide

44 Page

TEMPERATURE SETTINGS ON THE PCB

WITHOUT CONTROLLER

WARNING

• Adjust the appropriate DIP switches according to model and temperature as

shown below. DO NOT adjust the other DIP switches.

• Turn off the power supply to the water heater before changing the DIP switch

settings.

• Failure to observe these warnings could lead to carbon monoxide poisoning,

severe personal injury, or death.

There are two preset temperatures, 120 °F (50 °C) and 140 °F (60 °C), that you can select by changing the

DIP switch settings on the computer board without the controller. See below.

When the controller is in normal operation, the set temperature of the controller is given priority over the

set temperature of the DIP switch settings.

NOTE: The tables above show the correct DIP switch position for each temperature setting.

(Each black square represents a switch.) For the 110U and 310U, only adjust DIP switch No.

9. For the 510U, only adjust DIP switch No. 5 on the lower bank. Do not adjust the other DIP

switches for temperature adjustment.

• The temperature has been preset at the factory to 120 °F (50 °C).

DIP switches

Computer board

110U and 310U

120 °F (50 °C)

DEFAULT

140 °F (60 °C)

No. 9 : OFF

No. 9 : ON

OFF

1 2 3 4 5 6

7 8 9

OFF

1 2 3 4 5 6 7 8 9 10

Lower bank of

DIP switches

Computer board

Upper bank of

DIP switches

(Lower bank of DIP switches)

120 °F (50 °C)

DEFAULT

140 °F (60 °C)

No. 5 : OFF No. 5 : ON

510U

OFF

1 2 3 4 5 6

OFF

1 2 3 4 5 62 3 4 5 6

Normal Operaon

Owner's Guide

FLOW

Appliance/Use

Flow rate

GPM (US) L/min

Lavatory Faucet 1.0 3.8

Bath Tub 4.0 – 10.0 15.2 - 37.8

Shower 2.0 7.5

Kitchen Sink 1.5 5.6

Dishwasher 1.5 5.6

Washing machine 4.0 15.2

Household Flow Rates

Taken from UPC 2006

• The flow rate through the water heater is limited

to a maximum of 6.6 GPM (25 L/min) for the 110U

model, 8.0 GPM (30 L/min) for the 310U model, and

10.0 GPM (38 L/min) for the 510U model.

• The temperature setting, along with the supply

temperature of the water, will determine the flow

rate output of the unit.

• Please refer to the temperature vs. gallons per

minute charts on p. 60 to determine the likely flow

rates based on your local ground water temperature

and your desired outlet water temperature.

• Refer to the table to the top right for typical household plumbing fixture flow rates to determine what

the water heater can do in a household application.

45 Page

FREEZE PROTECTION SYSTEM

• This unit comes equipped with heating blocks to protect it from damage associated with freezing.

• For this freeze protection system to operate, there has to be electrical power to the unit. Damage

to the heat exchanger caused by freezing temperatures due to power loss is not covered under the

warranty. In cases where power losses can occur, consider the use of a backup power supply.

• The freeze protection system will activate when the air temperature inside the case or water in the heat

exchanger is less than 36.5 °F (2.5 °C).

• In any areas subject to freezing temperatures, the manufacturer highly recommends an indoor instal-

lation with an indoor model. In such an installation, freezing issues can occur if cold air enters through

the venting into the heat exchanger, whether by negative pressures within the installation location or

by strong outside winds.

• The manufacturer also highly recommends the use of a backflow preventer (sold separately)

to minimize the amount of cold air entering through the exhaust venting when the water heater is off.

• It is the installer’s responsibility to be aware of freezing issues and take all preventative measures. The

manufacturer will not be responsible for any damage to the heat exchanger as a result of freezing.

• If you will not be using your heater for a long period of time:

1. Completely drain the water out of the unit. Refer to p. 46.

2. Disconnect power to your heater.

This will keep your unit from freezing and being damaged.

Normal Operaon

Owner's Guide

Only pipes within the water heater are protected by the freeze protection system.

Any water pipes (hot or cold) located outside the unit will not be protected.

Properly protect and insulate these pipes from freezing.

NOTICE

MAINTENANCE AND SERVICE

• Clean the cold-water inlet filter. (Refer to "Unit Draining and Filter Cleaning" on this page.)

• Be sure that all openings for combustion and ventilation air are not blocked.

• The venting system should be checked annually for any leaks, corrosion, blockages or damage.

• The burner should be checked annually for dust, lint, grease or dirt.

• Keep the area around the water heater and terminations clear. Remove any combustible materials, gasoline,

flammable vapors, and liquids.

• If the relief valve discharges periodically, it may be due to thermal expansion in a closed water supply system.

Contact the water supplier or local plumbing inspector on how to correct this situation.

• Visually check the burner flames (see below) through the burner window in the burner assembly located at the

middle of the water heater.

The manufacturer recommends having the unit checked once a year or as necessary by a licensed technician. If

repairs are needed, any repairs should be done by a licensed technician.

• Turn off the electrical power supply and close the manual gas shutoff

valve and the manual water control valve before servicing.

• Failure to do so could result in serious personal injury or death.

WARNING

Sasfactory

Blue ame

Unsasfactory

Flame liing

above the

burner

Unsasfactory

Red or Yellow

ame

46 Page

UNIT DRAINING and FILTER CLEANING

1. Close the manual gas shutoff valve.

2. Turn off power to the unit and wait a couple of seconds. Turn on again.

3. Wait 30 seconds, and then turn off power to the unit.

4. Close the inlet water valve.

• If the heater is part of an Easy-Link or Multi-Unit System, close the inlet

and outlet water valves to isolate the heater. Then proceed to step 6.

5. Open all hot water taps in the house. When the residual water flow has

ceased, close all hot water taps.

6. Have a bucket or pan to catch the water from the unit’s drain plugs.

If Isolation valves are installed, open the drains to drain the water. If

isolation valves are not installed, unscrew the two drain plugs (large and

small) to drain the water out of the unit. Do not lose the o-rings that will

be on the two drain plugs.

7. Wait a few minutes to ensure all water has completely drained from the

unit.

8. Clean the filter: Check the water filter located within the cold inlet.

With a tiny brush, clean the water filter of any debris which may have

accumulated and reinsert the filter back into the cold water inlet.

9. Securely screw the drain plugs back into place.

Hand- tighten only.

Normal Operaon

Owner's Guide

Pressure

port

-Measuring inlet gas pressure-

The water heater cannot perform properly without sufficient inlet gas pressure. Below are instructions

on how to check the inlet gas pressure. THIS IS ONLY TO BE DONE BY A LICENSED PROFESSIONAL.

1. Shut off the manual gas valve on the gas supply line.

2. Remove the screw from the pressure port which is located on the gas inlet of the

water heater shown in the diagram on the right.

3. Connect the manometer to the pressure port and zero the manometer.

4. Re-open the manual gas valve. Verify that there are no gas leaks.

5. With all gas burning equipment off, take a reading of the static gas pressure and

make a note of it.

6. Measure gas supply pressure at maximum heater operation: Open hot water fau-

cets to create maximum flow. Press and hold the MAX button on the computer

board. Take a reading of the supply dynamic gas pressure with all gas burning

equipment running at maximum rate.

7. The static and dynamic pressures should be within the ranges specified on the heater's rating plate and the

table on p. 26.

8. The difference of static to dynamic pressure should not exceed 1.5" W.C. Pressure drops that exceed 1.5" W.C.

can indicate restricted gas flow, undersized gas lines, and/or undersized supply regulators. (NOTICE: In Canada,

the pressure drops cannot exceed those specified in CSA B149.1.)

9. Measure gas supply pressure at minimum heater operation: While water is flowing through the heater, press the

MIN button on the computer board. (Refer to the diagram below.) Take a supply gas pressure reading and verify

that it is within the specified inlet gas pressure range.

1. Turn off all electric power to the water heater if service is to be performed.

2. Turn the manual gas valve located on the outside of the unit to the OFF position.

3. Failure to follow these steps could lead to fire or explosion, resulting in personal injury

or death.

WARNING

110U / 310U

Computer board

MAX button

MIN button

510U

Computer board

MIN button

MAX button

Inlet

water valve

Drain plug

(Small)

Outlet

water valve

Drain plug with Filter (Large)

47 Page

TROUBLESHOOTING

GENERAL

PROBLEM SOLUTIONS

TEMPERATURE and AMOUNT OF HOT WATER

It takes a long time to

get hot water at the

fixtures.

• The time it takes to deliver hot water from the water heater to your

fixtures depends on the length of piping between the two. The longer

the distance or the bigger the pipes, the longer it will take to get hot

water.

• If you would like to receive hot water to your fixtures more quickly, you

may want to consider a hot water recirculation system. (p. 35)

The water is not hot

enough.

• Compare the flow and temperature. See the charts on p. 60.

• Check cross plumbing between cold water lines and hot water lines.

• Is the gas supply valve open fully? (p. 37)

• Is the gas line sized properly? (pp. 26 and 27)

• Is the gas supply pressure within specified limits? (pp. 26 and 46)

• Is the set temperature set too low? (pp. 42 and 44)

• Is the Easy Link or Multi-Unit system set up correctly?

The water is too hot. • Is the set temperature set too high? (pp. 42 and 44)

The hot water is not

available when a

fixture is opened.

• Make sure the unit has 120 VAC, 60 Hz power supply.

• Is the power button on the controller or inside the water heater turned

on?

• Is the gas supply valve open fully? (p.37)

• Is the water supply valve open fully? (p. 37)

• Is the filter on the cold water inlet clean? (p. 46)

• Is the hot water fixture sufficiently open to draw at least 0.5 GPM

(1.9 L/min) through the water heater? (p. 41)

• Is the unit frozen? (p. 45)

• Check for cross plumbing between the hot and cold water lines.

• Is the Easy Link or Multi-Unit system set up correctly?

The hot water turns

cold and stays cold.

• Is the flow rate enough to keep the water heater running? (p. 41)

• If there is a recirculation system installed, does the recirculation line have

enough check valves? (p. 35)

• Is the gas supply valve open fully? (p. 37)

• Is the filter on the cold water inlet clean? (p. 46)

• Are the fixtures clean of debris and obstructions?

Fluctuation in hot

water temperature.

• Is the filter on the cold water inlet clean? (p. 46)

• Is the gas line sized properly? (pp. 26 and 27)

• Is the supply gas pressure within specified limits? (pp. 26 and 46)

• Check for cross connection between cold water lines and hot water lines.

• Is the Easy Link or Multi-Unit system set up correctly?

Troubleshoong

Owner's Guide

48 Page

PROBLEM SOLUTIONS

WATER HEATER

Unit does not ignite

when water goes

through the unit.

• Is the flow rate over 0.5 GPM (1.9 L/min)? (p. 41)

• Check the filter on the cold water inlet. (p. 46)

• Check for reverse connection and cross connection.

• If you use the remote controller, is the power button turned on?

• Check if the inlet water temperature is too high. If it is too close to

the set temperature, the water heater will not activate.

• Is the gas supply turned on?

• Is power available to the unit? If so, is the power button on the

controller or inside the water heater turned on?

The fan motor is

still spinning after

operation has stopped.

• This is normal. After operation has stopped, the fan motor keeps

running from 15 to 70 seconds in order to re-ignite quickly, as well

as purge all the exhaust gas out of the flue.

Unit sounds abnormal

while in operation

• Contact the manufacturer at 1-877-737-2840.

Buit-in controller

and remote controller

Built-in and remote

controller do not

display anything when

the power button is

turned on.

• Make sure the unit is supplied with power.

• For the remote controller: Make sure the connection to the unit is

correct. (pp. 30 and 31)

When the

controller is

turned ON, STAND

BY LED is lit.

Buit-in controller

• When the unit has not operated for five minutes or more, the

display turns off to conserve energy.

• Although the controller of the parent unit will display the set

temperature at the Easy-Link System, the controller of the child

unit will not display the set temperature.

An ERROR code is

displayed.

• Please see pp. 49 to 52.

EASY-LINK SYSTEM

510U model only

How are the unit

numbers assigned?

• For an Easy-Link System, the Parent unit is always labeled #1 and all

other subsequent Child units are numbered randomly.

• To check which numbers are assigned to which Child units, push the

button on the computer board of any Child unit as shown below.

The unit number will be displayed on the controller of each Child

unit. (Refer to p. 33.)

Buon to check unit numbers

Troubleshoong

Owner's Guide

49 Page

Troubleshoong

Owner's Guide

Error code

ERROR CODES

-General-

• The units have self-diagnostic functions for safety and convenience when troubleshooting.

• If there is a problem with the installation or the unit, the error code will be displayed on the built-in

controller or remote controller.

• Consult the table on the following pages for the description of each error code.

-Single unit Installaons-

Example: If your unit has the “321” error code (which signifies an inlet thermistor failure)

• Indicator on the built-in controller

and/or remote controller: “321” will be displayed

on the screen.

• Green LED on the computer board: The green LED on the computer board will indicate this code with

two flashes every 1/2 second. The pattern will repeat with a three second delay between patterns.

Error code Green LED

on on on on

on on

oﬀ oﬀ oﬀ oﬀ oﬀ

321

Error Indication

Green LED ashes error code

110U and 310U 510U

Error code indicator on

the built-in controller

Error code indicator on

the remote controller

Error Code

on the temperature

controller

Green LED

The number

of ﬂashes

Flash paern

031 701 711

One

311 321 331

391 441

Two

111 121

Three

611 651 661

Four

101 991

Five

510 551 721

Six

on on

oﬀ

0.5 sec. on, O.5 sec. oﬀ 3 sec. oﬀ

50 Page

-For the 510U model in an Easy-Link System-

Error codes will be displayed differently with units installed within an Easy-Link System, not only to show

what the error code is, but to also indicate which unit within the system has the error code. Below is a

sample of how the error code of "321" is displayed in an Easy-Link System.

Example: If Unit #2 has the “321” error code (inlet thermistor failure)

• Indicator on the built-in controller

and/or remote controller of Parent unit:

“321” and "2" will intermittently flash on

the display.

Unit #Error code

100209924 (TM-RE42)

Unit #1

PARENT

Unit #2

CHILD

Unit #4

CHILD

Unit #3

CHILD

100209924 (TM-RE42)

Unit #1

PARENT

Unit #2

CHILD

Unit #4

CHILD

Unit #3

CHILD

Error code Green LED

on on on on

on on

oﬀ oﬀ oﬀ oﬀ oﬀ

321

Green LED on

the computer board

Outdoor model installation

• Unit #2:

The green LED on the computer board will be

flashing twice, just like in the single unit example.

• Unit #3 and #4:

The green LED on the computer board will stay off.

Indoor model installation

• Unit #2:

"321" will intermittently flash on

the display. The green LED on

the computer board will be flashing

twice, just like in the single

unit example.

• Unit #3 and #4:

These units will not display anything,

as the error code does not pertain to them.

51 Page

-Fault Analysis of Error Codes-

If the error code is displayed on the computer board of the water heater or the controller, please check

the following. After checking, consult with the manufacturer.

Troubleshoong

Owner's Guide

Remote

Green

LED

Malfunction

description

Diagnosis

031

One Flash

Incorrect DIP switch

setting

• Check the DIP switch settings on the PCB (Part #701).

101

Five Flashes

Warning for the “991”

error code

• Check the gas type of the water heater.

• Check if there is any blockage in the intake air and/or

exhaust.

• Check if there is enough distance between the exhaust

and air intake terminals.

• Check the altitude/elevation of area of where the water

heater is installed.

• Check if there is grease and/or dirt in the burner (Part #101)

and the fan motor (Part #103), especially if the water heater

has been installed in a contaminated area.

111*

Three Flashes

Ignition failure • Check if the Hi-limit switch (Part #412) is properly

functioning.

• Check for connection/breakage of wires (Part #008, 413, 708,

709), burn marks on the computer board (Part #701), and/or

soot on the flame rod (Part #107) and the ignitor (Part #108).

• Ensure that the gas supply is turned on. If your water

heater has been properly converted to use propane,

ensure that the tank is not empty.

• Check if there is a buzzing spark ignition sound coming

from the burner (Part #101) when water heater prepares

for combustion.

• Listen for the double “clunk” sound coming from the gas

valve assembly (Part #102) when the water heater goes

into combustion.

• Check if there is leaking from heat exchanger (Part #401).

121*

Three Flashes

Loss of flame • Check if the Hi-limit switch (Part #412) is functioning

properly.

• Check for connection/breakage of wires (Part #008, 413,

708, 709), burn marks on the computer board (Part #701),

and/or soot on the flame rod (Part #107) and the ignitor

(Part #108).

• Ensure that the gas supply is turned on. If your water

heater has been properly converted to use propane,

ensure that the tank is not empty.

• Check if there is leaking from the heat exchanger (Part #401).

311*

Two Flashes

110U & 310U:

Outlet thermistor

failure

510U:

Heat exchanger

thermistor failure

• Check for connection/breakage of wires and/or debris on

the thermistor (Part #407, 408, 411, 713).

321*

Two Flashes

Inlet thermistor failure

331*

Two Flashes

Outlet thermistor

failure

(510U model only)

391

Two Flashes

Air-fuel ratio rod failure • Check for connection/breakage of wires (Part #709) and/

or soot on the AFR rod (Part #107).

441

Two Flashes

Flow sensor failure

(Only Easy-Link &

Multi-Unit System)

• Check for connection/breakage of wires and/or debris on

the flow sensor impeller (Part #402).

• Check water filter. Ensure isolation valves are open.

*These error codes will be cleared when water flow stops.

52 Page

Troubleshoong

Owner's Guide

Remote

Green

LED

Malfunction

description

Diagnosis

510

Six Flashes

Abnormal main gas

solenoid valve

• Check for connection/breakage of wires (Part #708) and/

or burn marks on the computer board (Part #701).

551

Six Flashes

Abnormal gas

solenoid valve

• Check for connection/breakage of wires (Part #714) and/

or burn marks on the computer board (Part #701).

611*

Four Flashes

Fan motor fault • Check for connection/breakage of wires, dust buildup

in the fan motor (Part #103) and/or burn marks on the

computer board (Part #701).

• Check for frozen/corrosion of connectors (Part #103).

651

Four Flashes

Flow adjustment

valve fault (Only

Easy-Link & Multi-Unit

System)

• Inspect the flow adjustment valve (Part #402), for

connection/breakage of wires, locked motor drive due to

scale buildup, and/or water leakage.

661*

Four Flashes

Bypass valve fault

(510U model only)

• Inspect the bypass valve (Part #403), for connection/

breakage of wires, locked motor drive due to scale

buildup, and/or water leakage.

701*

One Flash

Computer board fault • Check the outlet thermistor (Part #408) as it may need to

be cleaned.

• Check for connection/breakage of wires (Part #714).

711*

One Flash

Gas solenoid valve

drive circuit failure

• Refer to the 111 and 121 error codes.

721*

Six Flashes

False flame detection • Check if condensate drain is installed on the vent collar of

the water heater.

• Check if there is leaking from heat exchanger (Part #401).

741

N/A

Miscommunication

between water heater

and remote controller

• Inspect the connections between the water heater and

remote controller.

• Check the power supply of the water heater.

751

N/A

Miscommunication

between water heater

and built-in controller

• Inspect the connections between the water heater and

built-in controller.

• Check the power supply of the water heater.

761

N/A

Miscommunication in

Easy-Link system

• Check if the connections between the parent unit and the

child units are correct. Refer to p. 33.

• Verify that each unit has power and that its power switch

above the computer board is in the ON position.

991

Five Flashes

Imperfect

combustion

• Check the gas type of the water heater.

• Inspect the environment around the water heater.

Determine how long the unit has been installed.

• Check the altitude/elevation of the area of where the

water heater is installed.

• Check if there is any blockage in the intake air and/or

exhaust.

• Check to make sure that there is enough distance between

the exhaust and air intake terminals.

• Check if there is grease and/or dirt in the burner (Part

#101) and the fan motor (Part #103), especially if the

water heater has been installed in a contaminated area.

*These error codes will be cleared when water flow stops.

53 Page

COMPONENTS DIAGRAM

Components Diagram

Owner's Guide

Case assembly

006

004

052

003

052

003

001

005

007

715

002

052

050

704

052

050

704

710

008

002

Built-in temperature controller

722

721

065

54 Page

510U110U and 310U

701

705

103

402

707

713

403

714

709

708

711

705

103

709

402

711

707

714

407

408

708

701

064

713

712

721

Computer board assembly

Surge box assembly

Components Diagram

Owner's Guide

120

705

053

062

706

703

068

704

705

716

55 Page

Components Diagram

Owner's Guide

Burner assembly

153

154

103

401

103

054

118

053

105

106

112

708

401

150

117

116

121

062

114

701

102

119

101

107

707

152

151

057

063

062

067

062

055

056

052

055

053

111

113

061

110

711

714

053

057

060

109

115

054

702

053

108

104

122

104

053

052

709

Manifold

assembly

Burner

assembly

Exhaust section (Outdoor model)

LP Conversion Kit

130

131

510U

56 Page

Components Diagram

Owner's Guide

Water Way assembly

458

462

403

456

460

411

459

454

413

450

463

452

059

412

414

453

066

462

417

461

401

460

456

458

414

416

451

414

451

402

404

407406

405

460

456

458

461

052

415

058

454

457

052

408

410

409

415

058

454

455

052

401

To Water

inlet secon

To Water

outlet secon

458

462

414

451

414

052

To Water

inlet secon

To Water

outlet secon

Bypasssecon

510U

Water outlet section

Water inlet section

110U 310U

510U

57 Page

Parts List

Owner's Guide

PARTS LIST

Item # Description

Part #

110U, 310U and

510U models

AT-KJr3U-IN/OS,

AT-K5U-IN/OS and

AT-D3U-IN/OS

001 Case assembly for Indoor models

for Outdoor models

N/A

EK596

EK597

002 Front cover for Indoor models

for Outdoor models

N/A

EK598

EK599

003

004

005

006

007

008

Bracket

Intake air port assembly

Junction box

Power supply cord assembly

Back guard panel

Overheat-cut-off fuse for combustion chamber

N/A

100074668

100074603

N/A

100074201

EK455

EK600

EK190

EKK4D

EK601

EM484

050

051

052

053

Truss screw M4×12 (W/Washer) SUS410

Truss screw M4×10 (W/Washer) SUS410

Truss screw M4×10 (Coated) SUS3

Truss screw M4x10 SUS

100074210

100074509

100074211

100074245

EW000

EW001

EW002

EW003

054

055

056

057

Hex head screw M4×12 (W/Washer) SUS3

Hex head screw M4x8 FEZN

Pan screw M4x10 FEZN

Pan Screw M3x10 SUS

100074510

100074248

100074247

100074511

EW004

EW005

EW006

EW008

058

059

060

061

062

063

Tapping screw M4x6 SUS3 Truss head

Tapping screw M3x6 SUS3 Pan head

Screw M3x6 SUS3 Binding head

Pan screw M4x8 MFZN

Tapping screw M4x14 SUS410 Truss head

Screw M3x12 BSNI Raised counter sunk head

100074512

100074272

100074514

100074244

100076450

100074515

EW009

EW00A

EW00B

EW00D

EW00E

EW00X

064

065

066

067

068

Screw M3x6 BSNI Binding head

Pan screw M4x20 SUS410

Truss screw M4x8 SUS3

Tap tight screw M4x12 FEZN

Truss screw M4x10 MFZN3

N/A

100074385

N/A

EW016

EW018

EW02A

EKK31

EX014

101

102

Burner assembly

Manifold with gas valve assembly NA

100224092

100224093

EK554

EK555

103 Fan motor for Indoor models

Fan motor for Outdoor models

100074606

100074228

EK109

EKK25

104 Fan motor plate for Indoor models

Fan motor plate for Outdoor models

100074466

N/A

EM381

EK140

105

106

107

108

109

110

Burner window

Rod holder gasket

Flame rod with AFR function

Igniter rod

Rod holder

Rod cap

100076535

100224097

100224098

100224099

100224100

100076319

EKN58

EK559

EK560

EK561

EK562

EK462

111

112

113

Burner damper

Manifold gasket A

Manifold gasket B

100270556

100224102

100224103

EK602

EK564

EK565

114

115

116

117

Pressure port

Combustion chamber tube

Gas inlet

Gas inlet ring

100074227

100074528

100074235

100074234

EKK2D

EX019

EKK1E

EKK2Z

58 Page

Item # Description

Part #

110U, 310U and

510U models

AT-KJr3U-IN/OS,

AT-K5U-IN/OS and

AT-D3U-IN/OS

118

119

Burner gasket

Burner holder gasket

100224105

100224106

EK567

EK568

120

121

122

Surge box plate

PCB fixing plate

Thermostat

100074360

N/A

100074369

EK436

EK603

EKJ59

130

131

LP Conversion kit

Manifold gasket

100270585

100281157

EK604

EK592

150

151

152

153

154

O-ring P18 NBR (Manifold)

O-ring P20 NBR (Black)

Silicon ring for Outdoor models

Rain protection plate in Exhaust chamber for Outdoor models

Exhaust port for Outdoor models

N/A

100074242

100074390

100074400

100074403

EK570

EK042

EKK3G

EKK53

EKK56

401 Heat exchanger assembly for 110U and 310U Indoor

for 110U and 310U Outdoor

for 510U Indoor

for 510U Outdoor

100270557

100270558

100270559

100270560

EK605

EK606

EK607

EK608

402

403

404

405

406

Flow adjustment valve / Flow sensor

Bypass valve for 510U model

Water inlet

Inlet drain plug

Inlet water filter

100074624

100074625

100074377

100074381

100074382

EK129

EKD58

EKK1U

EKK2B

EKK2C

407 Inlet thermistor for 110U and 310U

Inlet thermistor for 510U

100074398

100224109

EKK4J

EK573

408 Outlet thermistor for 110U and 310U

Outlet thermistor for 510U

100074680

100224110

EK207

EK574

409

410

411

Water outlet

Outlet drain plug

Heat exchanger thermistor for 510U model

100074627

100074264

100224111

EK104

EK239

EK575

412 Hi-Limit switch for 110U and 310U

Hi-Limit switch for 510U model

100074412

100074280

EM212

EKN34

413

414

415

416

417

Overheat-cut-off fuse for heat exchanger

Pipe heater

Inlet heater

Pipe inlet

Joint outlet

100074252

100074682

100074629

100270581

100224113

EX02A

EK209

EK105

EK609

EK577

450

451

452

453

Fuse fixing plate 40

Heater fixing plate 16

Fuse fixing plate 18

Pipe heater fixing plate

N/A

100074310

N/A

EK616

EK031

EK476

EK610

454

455

456

457

O-ring P4 FKM

O-ring P6 FKM

O-ring P14 FKM

O-ring P15 FKM

100076303

100076305

100076306

100076307

EZM04

EZM06

EZM14

EZM15

458

459

460

461

O-ring P16 FKM

Fastener “4-11” for 510U model

Fastener “14-22”

Fastener “16A”

100076308

100074282

100074290

100074410

EZM16

EKH30

EKK24

EM192

462

463

Fastener “16-25A”

Silicon ring for Indoor models

100074389

100074250

EKK39

EKN50

Parts List

Owner's Guide

59 Page

Item # Description

Part #

110U, 310U and

510U models

AT-KJr3U-IN/OS,

AT-K5U-IN/OS and

AT-D3U-IN/OS

701 Computer board for 110U model

for 310U model

for 510U model

100270582

100270583

100270584

EK611

EK612

EK613

702

703

704

Remote fixing plate for 510U

Surge box

120 VAC wire for Indoor models

for Outdoor models

100074644

100076100

100074601

100074323

EK152

EK280

EK146

EKK3C

705

706

Switch wire

120 VAC Power ON-OFF switch

N/A

EK614

EK590

707

708

Remote controller wire for 110U and 310U

for 510U

Gas valve wire

100074649

100074650

N/A

EK189

EK165

EK585

709

710

711

Flame rod wire

Cable strap

Igniter assembly

N/A

100074640

EK586

EW022

EK153

712

713

714

715

716

Computer board cover

24V cables for 510U

Proportional gas valve wire

Rubber grommet for Indoor models

Surge box cover

100074458

N/A

100074642

100074655

N/A

EM329

EK587

EK112

EK184

EK615

721

722

Temperature controller

Controller fixing plate

100074660

N/A

EK173

EK588

N/A Communication cable for linking 100076516 EKK0J

Parts List

Owner's Guide

60 Page

OUTPUT TEMPERATURE CHART

Chart is based on properly sized gas line

Output Temperature Chart

Owner's Guide

110U

Output Temperature vs. GPM (Max. 6.6 GPM) with Various Inlet Water Temperature

Output Hot Water GPM

Set Temp. (°F)

Incoming Temp. (°F)

*When the set temperature is 130 °F (55 °C) or higher, maximum flow rate is limited to 8.0 GPM.

510U

Output Temperature vs. GPM (Max. 10.0 GPM) with Various Inlet Water Temperature

Output Hot Water GPM

Set Temp. (°F)

Incoming Temp. (°F)

310U

Output Temperature vs. GPM (Max. 8.0 GPM) with Various Inlet Water Temperature

Output Hot Water GPM

Set Temp. (°F)

Incoming Temp. (°F)

1W1101-2

DIR 2000534692 (REV. B)

AO Smith A.O. Smith GT15-510U-O Signature Series 10-GPM 199000-BTU Outdoor Natural Gas Tankless Water Heater

Product's Documents

Installation Manual

Specifications

AO Smith GT15-510U-O Questions and Answers