Installation, Operation and Maintenance InstructionsInstallation, Operation and Maintenance Instructions
– Read and Save These Instructions –
This manual is provided to acquaint you with the dehumidifier so that installation, operation and maintenance can
proceed successfully. Ultimate satisfaction depends on the quality of installation and a thorough understanding of
this equipment. The dehumidifier is built around tested engineering principles and has passed a thorough inspection
for quality of workmanship and function.
TS-976
02/17 Rev. A
1
4201 Lien Rd
Madison, WI 53704 Toll-Free 1-877-420-1330
www.QuestHydro.com info@QuestHydro.com
Specifications subject to change without notice.
Quest Dry
Quest CDG 174
Quest CDG 174 Installation, Operation and Maintenance Instructions
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Table of Contents
Safety Precautions ...........................................................3
1. Specifications ............................................................ 4
2. Operation .................................................................. 4
2.1 Transporting .......................................................... 4
2.2 Location ................................................................ 4
2.3 Electrical Requirements ......................................5
2.4 Condensate Removal ........................................... 5
2.5 Ducting ..................................................................5
2.6 POWER Button ................................................... 5
2.7 PURGE Button ....................................................5
2.8 Humidistat ............................................................6
2.9 HOURS Button ...................................................6
2.10 DEFROST Light .................................................6
2.11 Defrost Cycle .......................................................6
2.12 Low Pressure Control .........................................6
3. Maintenance ................................................................7
3.1 Air Filter ................................................................. 7
3.2 Storage ..................................................................7
4. Service ..........................................................................7
4.1 Warranty ................................................................7
4.2 Technical Description ..........................................8
4.3Troubleshooting .....................................................8
4.4 Refrigerant Charging .........................................10
4.5 Blower Replacement ..........................................10
4.6 Thermistor Replacement ...................................10
4.7 Condensate Pump Replacement ....................... 11
4.8 Gravity Drain Option ......................................... 11
5. Wiring Diagram ......................................................... 12
6. Service Parts .............................................................. 13
Warranty .................................................................... 14
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Safety Precautions
Read the installation, operation and maintenance instructions carefully before installing and operating
this device. Proper adherence to these instructions is essential to obtain maximum benefit from your
Quest CDG 174.
READ AND SAVE THESE INSTRUCTIONS
• The device is designed to be installed INDOORS IN A SPACE
THAT IS PROTECTED FROM RAIN AND FLOODING.
• Install the unit with space to access the back or side panels for
maintenance and service. DO NOT INSTALL UNIT WITH THE
SERVICE PANELS INACCESSIBLE.
• Avoid directing the discharge air at people, or over the water in
pool areas.
• If used near a pool or spa; be certain there is NO chance the unit
could fall into the water, be splashed and that it is plugged into a
GFI GROUND FAULT INTERRUPT OUTLET.
• DO NOT use the device as a bench or table.
• DO NOT place the device directly on structural members. Provide
vibration isolation in order to minimize operational vibration and/or
noise.
• A drain pan MUST be placed under the unit if installed above
a living area or above an area where water leakage could cause
damage
• If the supply cord is damaged, it must be replaced by the
manufacturer, its service agent or similarly qualified person in order
to avoid a hazard.
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1. Specifications
Part No. 4031170
Power 10 amps, 115 Vac, Grounded
Capacity 176 pints/day @ AHAM 80°F, 60% RH
Blower 380 CFM without external ducting
Cord 25’ 14ga Power Cord
Refrigerant 1 lb., 15 oz. R410a
Charge
Operating 33°F to 105°F
Range
Filters: 15.5” x 19.5” x 1.75” Pleated Media MERV-11
Duct Inlet - 12” Flex-Duct
Options: Outlet - 10” Lay-Flat
Warranty Five years;
1st year 100% of Parts and Labor
2nd-5th year 100% of Parts of sealed
refrigeration system.
Dimensions Width 20”, Depth 23”, Height 40”
Weight 135 lbs.
2. Operation
Place dehumidifier inside structure, place condensate hose into a drain, or a very large container, and turn on. To decrease
drying times, make sure all windows and doors are closed to the outside and seal o the wet area from any unaected areas.
2.1 Transporting
The Quest CDG 174 must always be upright when transported by vehicle. It may be tipped on to its handle and back for
loading and moving by hand.
2.2 Location
Note the following precautions when locating the Quest CDG 174:
• It is designed to be used INDOORS ONLY.
• If used in a wet area, plug it into a GROUND FAULT INTERRUPTER.
• DO NOT use the Quest CDG 174 as a bench or table.
• It must always be used in the upright position.
• The air inlet on top and the front outlet must be at least 1 foot from walls and other obstructions to air flow.
• If the humid area is very large, dehumidification can be improved by adding an outlet duct to circulate air to stagnant
areas (see Sec. 2.5).
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2.3 Electrical Requirements
The Quest CDG 174 can be plugged into a grounded 15 Amp circuit. At 80°F, 60% RH, it draws 10 Amps. Due to the
high percentage of a 15 Amp circuit’s capacity that the unit uses, the circuit should be dedicated to running it only. Amp
draw decreases at lower loads and increases at higher loads. At extremely high loads, a 20 Amp circuit may be required.
If an extension cord is required, it must have a minimum of 12 gauge conductors if 25 feet long or less and 10 gauge
conductors if greater than 25 feet long.
2.4 Condensate Removal
The Quest CDG 174 is equipped with an internal condensate pump to remove the water that is condensed during
dehumidification. This allows the condensate to be pumped 30’ with the attached hose. If the condensate must be
pumped more than 20 feet above the unit, a second pump must be added to relay the condensate.
2.5 Ducting
A detachable rectangular exhaust collar is supplied that will allow 10” round lay-flat duct to be attached to the Quest
CDG 174 outlet.
To attach ducting to a collar, put the plastic duct end through the collar center and roll the duct end outward so that it
overlaps the outside of the collar. The duct and collar may then be quickly attached to the Quest CDG 174 by snapping
the collar over the four screws at the blower outlet.
2.6 Power Button
Press the POWER button to turn the dehumidifier on or o. When starting the dehumidifier the display will show the
accumulated hours. Press the POWER button again to turn the dehumidifier o. The display will also power o.
2.7 Pump Purge Button
During normal operation the pump automatically cycles every four minutes. Press the PURGE button to remove
condensate manually from the reservoir. There are several ways to manually remove water from the reservoir:
1. Press the PURGE button once and the pump will run for 20 seconds
2. Press and hold the PURGE button and the pump will run for up to 30 seconds
3. Press the PURGE button while the dehumidifier is powered o and the pump will run for 30 seconds.
Always manually purge the water reservoir before transport or storage. Turn o the power and allow the plugged in dehu-
midifier to rest 15 minutes before the final purge.
2.8 Humidistat
Adjust the humidistat to the desired conditioned humidity. The humidistat has a range of 20% to 70% RH. “ON” will
operate the unit continuously regardless of humidity.
2.9 Hours Button
Pressing the HOURS button displays the hour meter when the unit is turned o but plugged into power. To reset job
hours, press and hold the HOURS button for 5 seconds when the unit is operating.
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2.10 Defrost Light
The DEFROST light turns on when the unit is in defrost mode indicating when the compressor is o.
DRYING TIP: Air’s ability to absorb moisture from wet surroundings and the Quest CDG 174’s ability to remove
moisture from that air is greatly improved at higher temperatures. We recommend that the area to be dried be heated
to over 70°F if possible. Less drying time will be required and eciency will improve.
2.11 Defrost Cycle
If the evaporator coil’s refrigerant temperature drops below the defrost set point, due to excessive frost formation, the
thermistor activates the solid state control and the defrost light. The control cycles the compressor “o” and “on” by
monitoring thermistor temperature. The air mover will continue to run, causing air to flow through the evaporator coil.
The air will melt the ice that formed on the evaprator.
When the air temperature and/or humidity increases, the evaporator temperature will rise and the thermistor will end the
defrost cycle restarting the compressor.
If the evaporator temperature does not reach the desired temperature, the compressor will start after 15 minutes. The
system will start a timed defrost cycle. The timed defrost cycle ensures the unit will continue to remove water from the
air in cool ambient conditions.
2.12 Low Pressure Control
If the low side refrigerant drops into a low pressure situation that may harm the compressor, the solid state controls will
sense the refrigerant conditions and shut o the compressor until the system automatically resets itself.
The solid state control monitors the refrigerant conditions to ensure the system is protecting compressor at all times.
The control protects the compressor from damage by monitoring cycles, pressures, and system performance.
3 Maintenance
3.1 Air Filter
The Quest CDG 174 is equipped with a pleated fabric air filter that must be checked regularly. The standard filter is a
MERV-11 high eciency filter. Operating the unit with a dirty filter will reduce the dehumidifier’s capacity and eciency
and may cause the compressor to cycle o and on unnecessarily on the defrost control. Quest recommends changing the
filter with each grow cycle.
IMPORTANT: DO NOT operate the unit without the filter or with a less eective filter as the heat exchanger and coils
inside the unit could become clogged and require disassembly to clean.
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3.2 Storage
There are two issues to consider when the Quest CDG 174 is stored between uses and both pertain to the water trapped
in the unit: damage caused by freezing and biological growth. The eect of the trapped water can be greatly reduced if
precautions are taken to remove as much as possible before storage.
1. Use the pump purge switch (see Sec. 2.7 and Fig. 4) to reduce the water level in the reservoir.
2. Stretch the hose flat to drain it completely.
If the unit will not be exposed to freezing temperatures, an alternative way to reduce biological growth is to flush the unit
with a bio-fungicide that is approved for use with copper, aluminum and polyethylene. To flush:
1. Run the hose to a drain.
2. Plug in the unit but do not turn it on.
3. Remove the air filter. Slowly pour a quart of the chemical through the top grille so that it drains into the black plastic
slots.
4. Hold in the pump purge switch to reduce the water level in the reservoir.
5. Flush with water.
4 Service
CAUTION: Servicing the Quest CDG 174 with its high pressure refrigerant system and high voltage circuitry presents
a health hazard that could result in death, serious bodily injury, and/or property damage. Only qualified service people
should service this unit.
4.1 Warranty
A warranty certificate has been enclosed with this unit; read it before any repair is initiated.
If a warranty repair is required, call the factory first at 1-800-533-7533 for warranty claim authorization and technical
assistance.
4.2 Technical Description
The Quest CDG 174 uses a refrigeration system similar to an
air conditioner’s to remove heat and moisture from incoming
air, and to add heat to the air that is discharged (see Fig. 2).
Hot, high pressure refrigerant gas is routed from the
compressor to the condenser coil (see Figure 2). The
refrigerant is cooled and condensed by giving up its heat to the
air that is about to be discharged from the unit. The refrigerant
liquid then passes through a filter/drier and capillary tubing
which cause the refrigerant pressure and temperature to drop.
It next enters the evaporator coil where it absorbs heat from
the incoming air and evaporates.
Figure 2: Refrigeration system of Quest
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The evaporator operates in a flooded condition, which means that all the evaporator tubes contain liquid refrigerant during normal
operation. A flooded evaporator should maintain constant pressure and temperature across the entire coil, from inlet to outlet.
The mixture of gas and liquid refrigerant enter the accumulator after leaving the evaporator coil. The accumulator prevents any
liquid refrigerant from reaching the compressor. The compressor evacuates the cool refrigerant gas from the accumulator and
compresses it to a high pressure and temperature to repeat the process.
4.3 Troubleshooting
No dehumidification, neither hour meter display nor compressor run and POWER button does not turn ON.
1. Unit unplugged or no power to outlet
2. Defective control board
3. Loose connection in internal wiring
No dehumidification, neither hour meter display nor compressor run with POWER button ON.
1. Defective control board
2. Loose connection in internal wiring
Some dehumidification, air mover runs continuously but compressor only runs sporadically.
1. Unit is in defrost cycle, DEFROST light on
2. Check to make sure humidistat is set high enough
3. Defrost thermistor defective or loose
4. Loose connection in compressor circuit
5. Defective compressor overload
6. Defective compressor
7. Defective relay
8. Low refrigerant charge
No dehumidification, air mover runs but compressor does not.
1. Bad connection in compressor circuit
2. Check to make sure humidistat is set high enough
3. Safety float switch closed, check pump reservoir
4. Defective compressor capacitor
5. Defective compressor overload
6. Defective compressor
7. Defective control board
8. Low refrigerant charge
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Air mover does not run. Compressor runs briefly but cycles on and o.
1. Loose connection in blower circuit
2. Obstruction prevents impeller rotation
3. Defective air mover
4. Defective control board.
Unit removes some water but not as much as expected.
1. Air temperature and/or humidity have dropped
2. Check to make sure humidistat is set high enough
3. Humidity meter and/or thermometer used are out of calibration
4. Unit has entered defrost cycle
5. Air filter dirty
6. Defective defrost thermistor
7. Low refrigerant charge
8. Air leak such as loose front cover
9. Defective compressor
10. Restrictive exhaust or inlet ducting
Unit runs but does not pump water.
1. Hose kinked or plugged
2. Pump motor defective
3. Pump check valve plugged
4. Bad connection in pump circuit
5. Hose disconnected internally
6. Defective control board
Unit pumps water automatically but not when PURGE button is pushed.
1. Bad connection in PURGE button circuit
2. Defective control board
Evaporator coil frosted continuously, low dehumidifying capacity.
1. Defrost thermistor loose or defective
2. Low refrigerant charge
Compressor runs with POWER button OFF.
1. Defective relay
2. Defective control board
3. Upper housing not sealed to tower
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4.4 Refrigerant Charging
If the refrigerant charge is lost due to service or leak, a new charge must be accurately weighed in. If any of the old charge is left in
the system, it must be removed before weighing in the new charge. Refer to the unit nameplate for the correct charge weight and
refrigerant type.
4.5 Blower Replacement
The blower has a PSC motor and internal thermal overload protection. If defective, the complete assembly must be replaced.
1. Unplug power cord
2. Remove the front cover
3. Remove the 5 screws attaching blower inlet ring
4. Remove the 4 screws mounting impeller to underside of base plate
5. Disconnect the blower leads
6. Reassemble the new blower using the above procedure in reverse
4.6 Thermistor Replacement
The defrost thermistor probe is inserted into the coil measuring coil temperatures and reacts accordingly.
To replace thermistor:
1. Remove top cover and filter
2. Remove 5 screws holding front filter bracket
3. Remove the filter bracket and foam block underneath
4. Remove the 4 screws holding the control panel in place
5. Pull the thermistor probe from the evaporator coil, reinsert the new probe into the existing hole
6. Route the thermistor wire along the side of the heat exchanger
7. Detach and remove old thermistor wire from board
8. Attach thermistor probe wire onto board
9. Reassemble unit
4.7 Condensate Pump Replacement
The internal condensate pump removes water that collects in the reservoir.
To replace the condensate pump:
1. Unplug the unit
2. Remove the rear skidplate
3. Unplug the pump wires from the wire harness
4. Remove the condensate hose and the screw attaching the pump bracket to the base
5. Replace the pump, hose, wiring, bolts, and cover in the reverse order
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4.8 Gravity Drain Option
If the condensate pump fails and cannot be replaced immediately, the Quest CDG 174 can be used by draining by gravity.
1. Unplug the unit and remove the front cover.
2. Push the plastic plug on the right side (see Fig. 4) out from inside the unit.
3. Locate the heavy vinyl hose that connects the drain pan to the condensate pump. Pull the end out of the pump.
4. Remove tie wrap holding drain tube to suction line.
5. Push that end of the vinyl hose through the hole in the right side.
6. Connect a garden hose and run it to a drain. Keep the hose as flat to the floor as possible to avoid air pockets that would
hinder draining. Placing the unit on something above the floor will also improve draining.
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5. Wiring Diagram
THERMISTOR
J5
J4
J1
J2
J3
CONTROL
BOARD
PART NO.
REV.
4036303
A
HUMIDISTAT
6
0
4
1
COMPRESSOR
RELAY
LOW PRESSURE
SWITCH
COMPRESSOR
R
C
S
PUMP
NC
NO
YEL
TERMINAL
BLOCK
WIRE
CAPACITOR
COMPRESSOR
CAPACITOR
IMPELLER
SAFETY
PROBE
IMPELLER
CAPACITOR
2, 6, 20 BLK 13, 16, 19 WHT
12 WHT
9, 10 YEL
8 GRY
19 WHTBLK
WHT20 BLK
BLU
21 BLK
18 WHT
17 BRN
7 BLK
6 BLK
5 VIO4 VIO3 VIO
2 BLK
3 VIO
22 BLK
GRY
L1 L2
11 WHT
1 BLK
15 RED
14 YEL 13, 18 WHT
15 RED
16 WHT
Figure 3: Electrical schematic of Quest CDG 174
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6 Service Parts
Item Description Qty Part No.
1 Top Cover 1 4035206
2 Top Cover Hinge 2 4027267
3 Wheel 12” Gray 2 4026304
4 Cotter Pin 3/32” 2 1284404
5 Air Filter 1.75 x 15.5 x 19.5 1 4021475
6 Hose Vinyl 0.56 ID x 24 1 4029894
7 Hose Vinyl 0.38 ID 1 4021909
8 Hose Vinyl 0.25ID x 33 1 4024916
9 Coupling Body 0.25 Tube 1 4024910
10 Coupling Insert 0.38 Tube 1 4023080
11 Control Board 1 4033674
12 Capacitor Compressor 55mfd 370V 1 4033032-06
13 Capacitor Impeller 15mfd 371V 1 4035235-07
14 Thermistor (not shown) 1 4034716-01
15 Cord (14ga, 25’) 1 4037569
16 Compressor 11.9KBTU R410a 1 4034763
17 Overload Compressor 1 4034033
18 Evaporator Coil 1 4034474-05
Item Description Qty Part No.
19 Condenser Coil 1 4028566
20 Condensate Pump 1 4034605-01
21 Fan Motorized Impeller 1 4026657
22 Inlet Ring 1 4034811
23 Wire Duct Collar 1 4028593
24 Relay SPST 100/120V 25A 1 1970010
25 Filter Drier (not shown) 1 4029510
26 Wire Harness (not shown) 1 4034895
27 Handle 1 4026094
28 Bolt M10-1.5 X 35 2 1177792
29 Washer M10 X 30 2 4025517
30 Hex Lock Nut M10-1.5 2 1223780
31 Humidity Controller 1 4027172
32 Knob 1 4021495
33 Skid Panel 1 4035913
1, 5, 8
7, 9, 10
3, 4
19
18
15
2
24
23
21, 22
16, 17
6
20
11
27, 28
29, 30
12
13
31, 32
Figure 4
33
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Quest CDG 174 Dehumidifier Limited Warranty
Warrantor:
Therma-Stor LLC
4201 Lien Rd
Madison, WI 53704
Telephone: 1-866-933-7486
Who Is Covered: This warranty extends only to the original end-user of the Quest CDG 174
dehumidifier, and may not be assigned or transferred.
Year One: Therma-Stor LLC warrants that, for one (1) year the Quest CDG 174 dehumidifier will operate free from any defects in
materials and workmanship, or Therma-Stor LLC will, at its option, repair or replace the defective part(s), free of any charge.
Year(s) Two Through Five: Therma-Stor LLC further warrants that for a period of five (5) years, the condenser, evaporator, and
compressor of the Quest CDG 174 dehumidifier will operate free of any defects in material or workmanship, or Therma-Stor LLC,
at its option, will repair or replace the defective part(s), provided that all labor and transportation charges for the part(s) shall be
borne by the end-user.
End-User Responsibilities: Warranty service must be performed by a Servicer authorized by Therma-Stor LLC. If the end-user
is unable to locate or obtain warranty service from an authorized Servicer, he should call Therma-Stor LLC at the above number
and ask for the Therma-Stor Service Department, which will then arrange for covered warranty service. Warranty service will be
performed during normal working hours.
The end-user must present proof of purchase (lease) upon request, by use of the warranty card or other reasonable and reliable
means. The end-user is responsible for normal care. This warranty does not cover any defect, malfunction, etc. resulting from
misuse, abuse, lack of normal care, corrosion, freezing, tampering, modification, unauthorized or improper repair or installation,
accident, acts of nature or any other cause beyond Therma-Stor LLC’s reasonable control.
Limitation and Exclusions: If any Quest CDG 174 Dehumidifier part is repaired or replaced, the new part shall be warranted for
only the remainder of the original warranty period applicable thereto (but all warranty periods will be extended by the period of
time, if any, that the Quest CDG 174 Dehumidifier is out of service while awaiting covered warranty service).
UPON THE EXPIRATION OF THE WRITTEN WARRANTY APPLICABLE TO THE Quest CDG 174 OR ANY PART
THEREOF, ALL OTHER WARRANTIES IMPLIED BY LAW, INCLUDING MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE, SHALL ALSO EXPIRE. ALL WARRANTIES MADE BY THERMA-STOR LLC ARE SET FORTH
HEREIN, AND NO CLAIM MAY BE MADE AGAINST THERMA-STOR LLC BASED ON ANY ORAL WARRANTY. IN
NO EVENT SHALL THERMA-STOR LLC, IN CONNECTION WITH THE SALE, INSTALLATION, USE, REPAIR OR
REPLACEMENT OF ANY Quest CDG 174 OR PART THEREOF BE LIABLE UNDER ANY LEGAL THEORY FOR ANY
SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES INCLUDING WITHOUT LIMITATION WATER DAMAGE
(THE END-USER SHOULD TAKE PRECAUTIONS AGAINST SAME), LOST PROFITS, DELAY, OR LOSS OF USE OR
DAMAGE TO ANY REAL OR PERSONAL PROPERTY.
Some states do not allow limitations on how long an implied warranty lasts, and some do not allow the exclusion or limitation of
incidental or consequential damages, so one or both of these limitations may not apply to you.
Legal Rights: This warranty gives you specific legal rights, and you may also have other rights which vary from state to state.
