WARNING:
This product and accessories may contain a chemical known to the
State of California to cause cancer and birth defects or other
reproductive harm.
For more information about this regulation: www.P65Warnings.ca.gov
9.800-078.0-T 04/17/18
HDS Series
Hot Water - Electric Powered - Diesel Heated
Operator’s Manual
Pressure Washer
MODELS: HDS 3.9/20 Ea Cage
1.575-505.0
HDS 3.5/30 Ea Cage
1.575-508.0
HDS 3.5/30 Eb Cage
1.575-509.0
HDS 3.5/30 Ec Cage
1.575-510.0
To locate your local Kärcher
Commercial Pressure Washer
Dealer nearest you, visit
2 Karcher HDS 505, 508, 509, 510 Operator’s Manual 9.800-078.0 - T
Machine Data Label
3
Table of Contents
Machine Data Label. . . . . . . . . . . . . . . . . . . . . . . . . .2
Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . .3
How To Use This Manual . . . . . . . . . . . . . . . . . . . . .4
Safety
Introduction & Safety Information . . . . . . . . . . . . . . .5
Important Safety Information. . . . . . . . . . . . . . . . . . .6
Operations
Component Identification . . . . . . . . . . . . . . . . . . . . .9
Assembly Instructions. . . . . . . . . . . . . . . . . . . . . . .10
Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Operating Instructions. . . . . . . . . . . . . . . . . . . . . . .12
Detergents & General Operating Techniques. . . . .13
Thermal Pump Protection. . . . . . . . . . . . . . . . . . . .13
Cleaning Tips . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Rinsing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Shutting Down And
Clean-Up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Maintenance
Preventative Maintenance . . . . . . . . . . . . . . . . . . .16
Maintenance And Service. . . . . . . . . . . . . . . . . . . .16
Unloader Valves . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Winterizing Procedure. . . . . . . . . . . . . . . . . . . . . . .16
High Limit Hot Water Thermostat . . . . . . . . . . . . . .16
Pumps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Cleaning of Coils. . . . . . . . . . . . . . . . . . . . . . . . . . .17
Rupture Disk. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Fuel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Ignition Circuit. . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Electrode Setting. . . . . . . . . . . . . . . . . . . . . . . . . . .18
Burner Nozzle. . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
Oil Burner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Maintenance Charts . . . . . . . . . . . . . . . . . . . . . . . .20
Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Parts
Karcher HDS 1.575-505.0, 508.0, 509.0, 510.0 . . 24
Control Panel - 1.575-505.0, 508.0, 509.0, 510.0. 28
Float Tank - 505.0, 508.0, 509.0, 510.0 . . . . . . . . 30
Auto Start / Stop 505.0, 508.0, 509.0, 510.0. . . . . 33
Auto Start / Stop - Steam Options 505.0, 508.0,
509.0, 510.0. . . . . . . . . . . . . . . . . . . . . . . . . . 34
Pump - 1.575-505.0, 508.0, 509.0, 510.0. . . . . . . 36
Steam Options - 1.575-505.0, 508.0, 509.0, 510.0 37
Hose & Spray Gun . . . . . . . . . . . . . . . . . . . . . . . . 38
UU1 Unloader Valve . . . . . . . . . . . . . . . . . . . . . . . 40
KM.3 Series Pump . . . . . . . . . . . . . . . . . . . . . . . . 42
Wayne Burner. . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Karcher HDS 505, 508, 509, 510 Operator’s Manual 9.800-078.0 - T
4
How To Use This Manual
This manual contains the following sections:
• How to Use This Manual
•Safety
• Operations
• Maintenance
• Parts List
The HOW TO USE THIS MANUAL section will tell you
how to find important information for ordering correct
repair parts.
Parts may be ordered from authorized dealers. When
placing an order for parts, the machine model and
machine serial number are important. Refer to the
MACHINE DATA box which is filled out during the
installation of your machine. The MACHINE DATA box
is located on the inside of the front cover of this manual.
The model and serial number of your machine will be
found on a decal attached to the pressure washer.
The SAFETY section contains important information
regarding hazardous or unsafe practices of the
machine. Levels of hazards are identified that could
result in product damage, personal injury, or severe
injury resulting in death.
The OPERATIONS section is to familiarize the operator
with the operation and function of the machine.
The MAINTENANCE section contains preventive main-
tenance to keep the machine and its components in
good working condition. They are listed in this general
order:
• Preventative Maintenance
• Maintenance And Service
• Unloader Valves
• Winterizing Procedure
• High Limit Hot Water Thermostat
• Pumps
• Cleaning of Coils
• Rupture Disk
•Fuel
• Ignition Circuit
• Electrode Setting
• Burner Nozzle
• Karcher Clearfire Oil Burner
• Burner Air Adjustment
• Maintenance Charts
• Oil Change Record
• Troubleshooting
The PARTS LIST section contains assembled parts
illustrations and corresponding parts list. The parts lists
include a number of columns of information:
• REF – column refers to the reference number
on the parts illustration.
• PART NO. – column lists the part number for
the part.
• QTY – column lists the quantity of the part used
in that area of the machine.
• DESCRIPTION – column is a brief description
of the part.
• NOTES – column for information not noted by
the other columns.
NOTE: If a service or option kit is installed on your
machine, be sure to keep the KIT INSTRUCTIONS
which came with the kit. It contains replacement parts
numbers needed for ordering future parts.
NOTE: The manual part number is located on the
lower right corner of the front cover.
Model:
Date of Purchase:
Serial Number:
Dealer:
Address:
Phone Number:
Sales Representative:
Karcher HDS 505, 508, 509, 510 Operator’s Manual 9.800-078.0 - T
5
Safety
Introduction & Safety Information
Thank you for purchasing this Pressure Washer.
We reserve the right to make changes at any time
without incurring any obligation.
Owner/User Responsibility
The owner and/or user must have an understanding of
the manufacturer’s operating instructions and warnings
before using this pressure washer. Warning information
should be emphasized and understood. If the operator
is not fluent in English, the manufacturer’s instructions
and warnings shall be read to and discussed with the
operator in the operator’s native language by the
purchaser/owner, making sure that the operator
comprehends its contents.
Owner and/or user must study and maintain for future
reference the manufacturers’ instructions.
The operator must know how to stop the machine
quickly and understand the operation of all controls.
Never permit anyone to operate the engine without
proper instructions.
SAVE THESE INSTRUCTIONS
This manual should be considered a permanent
part of the machine and should remain with it if
machine is resold.
When ordering parts, please specify model and
serial number. Use only identical replacement
parts.
This machine is to be used only by trained
operators
Karcher HDS 505, 508, 509, 510 Operator’s Manual 9.800-078.0 - T
6
Safety
Important Safety Information
WARNING: To reduce the risk of
injury, read operating instruc-
tions carefully before using.
AVERTISSEMENT: Pour réduire
le risque de blessures, lire
attentivement les instructions
de fonctionnement avant l'utili-
sation.
1.Read the owner's manual thor-
oughly. Failure to follow instruc-
tions could cause malfunction of the machine and
result in death, serious bodily injury and/or property
damage.
2. Know how to stop the machine and bleed pressure
quickly. Be thoroughly familiar with the controls.
3. Stay alert — watch what you are doing.
4. All installations must comply with local codes.
Contact your electrician, plumber, utility company
or the selling dealer for specific details. If your
machine is rated 250 volts or less, single phase a
ground fault circuit interrupter (GFCI) will be
provided. If rated more than 250 volts, or more
than single phase this product should only be
connected to a power supply protected by a GFCI.
DANGER: Improper connection of the equipment-
grounding conductor can result in a risk of electro-
cution. Check with a qualified electrician or service
personnel if you are in doubt as to whether the
outlet is properly grounded. Do not modify the plug
provided with the product - if it will not fit the outlet,
have a proper outlet installed by a qualified electri-
cian. Do not use any type of adapter with this
product
DANGER : Une mauvaise connexion du conducteur
de terre de l'équipement peut entraîner un risque
d'électrocution. Vérifier auprès d'un électricien
qualifié ou du personnel d'entretien si vous avez
des doutes quant à savoir si lasortie est correcte-
ment mise à la masse.
DANGER: Keep wand, hose,
and water spray away from
electric wiring or fatal electric
shock may result.
DANGER :Garder la lance, le
boyau et le jet d'eau à l'écart de
tout câblage électrique ou des
chocs électriques mortels pour-
raient survenir.
5.To protect the operator from
electrical shock, the machine must be electrically
grounded. It is the responsibility of the owner to
connect this machine to a UL grounded receptacle
of proper voltage and amperage ratings. Do not
spray water on or near electrical components. Do
not touch machine with wet hands or while
standing in water. Always disconnect power before
servicing.
WARNING: Flammable liquids
can create fumes which can
ignite, causing property
damage or severe injury.
AVERTISSEMENT : Des
liquides inflammables peuvent
produire des vapeurs qui
peuvent s'enflammer, causant
ainsi des dommages àla
propriété ou des blessures
graves.
WARNING: Risk of explosion — Operate only where
open flame or torch is permitted.
AVERTISSEMENT : Risque d'explosion - Utiliser
uniquement dans des endroits où l'utilisation d'une
flamme nue ou d'une torche est permise.
6. In oil burning models, use only kerosene, No. 1
home heating fuel, or diesel. If diesel is used, add a
soot remover to every tankful.
WARNING: Risk of fire — Do not
add fuel when the product is
operating or still hot.
AVERTISSEMENT : Risque
d'incendie - Ne pas ajouter de
carburant pendant que la
machine fonctionner ou est
encore chaude.
WARNING
READ OPERATOR’S
MANUAL THOROUGHLY
PRIOR TO USE.
OPERATIONS
SAFETY
MAINTENANCE
DANGER
KEEP WATER
SPRAY AWAY FROM
ELECTRICAL WIRING.
WARNING
RISK OF EXPLOSION:
OPERATE ONLY WHERE
OPEN FLAME OR TORCH
IS PERMITTED
WARNING
RISK OF FIRE.
DO NOT ADD FUEL
WHEN OPERATING
MACHINE.
Karcher HDS 505, 508, 509, 510 Operator’s Manual 9.800-078.0 - T
7
Safety
WARNING: Do not use gasoline crankcase draining
or oil containing gasoline, solvents or alcohol.
Doing so will result in fire and/or explosion.
AVERTISSEMENT : Ne pas utiliser d'essence, de
drainage du carter de moteur ou d'essence conte-
nant de l'huile, de solvants ou de l'alcool. Ne pas
traiter les solvants, les huiles pures, etc. Agir de la
sorte risquerait de créer un incendie et/ou une
explosion.
7. Oil burning appliances shall be installed only in
locations where combustible dusts and flammable
gases or vapors are not present. Do not store or
use gasoline near this machine.
8. Do not allow acids, caustic or abrasive fluids to
pass through the pump.
9. Never run pump dry or leave spray gun closed
longer than 1-2 minutes.
10. Keep operating area clear of all persons.
WARNING: High pressure spray
can cause paint chips or other
particles to become airborne
and fly at high speeds. To avoid
personal injury, eye, hand and
foot safety devices must be
worn.
AVERTISSEMENT : Un jet haute
pression peut écailler la
peinture ou provoquer l'émis-
sion d'autres particules dans
l'air et leur projection à hautes vitesses.Pour éviter
les lésions corporelles, une protection des yeux,
du visage, des mains et des pieds doit être portée
lors de l'utilisation de cet équipement.
Always wear properly rated eye protection such as
safety goggles or face shield while spraying.
(Safety glasses do not provide full protection.)
WARNING: This machine
exceeds 85 db. Appropriate ear
protection must be worn.
AVERTISSEMENT : Cette
machine excède 85 dB et une
protection de l'ouïe appropriée
doit être portée.
WARNING: Hot discharge fluid.
Do not direct discharge stream
at persons or animals.
AVERTISSEMENT : Liquide de
décharge chaud. Ne pas
décharger directement le jet
vers des personnes ou des
animaux, car cela risquerait de
causer des blessures graves ou
même la mort.
WARNING: This machine produces hot water and
must have insulated components attached to
protect the operator.
AVERTISSEMENT : Cette machine produit de l'eau
chaude et doit comporter des composants isolés
attachés pour protéger l'opérateur.
WARNING: Risk of injury. Hot
surfaces can cause burns. Use
only designated gripping areas
of spray gun and wand. Do not
place hands or feet on non-
insulated areas of the pressure
washer.
AVERTISSEMENT : Risque de
blessures. Les surfaces
chaudes peuvent causer des
brûlures. Utiliser uniquement
les zones de prise désignées du pistolet pulvérisa-
teur et de la lance.Ne pas placer les mains ou les
pieds sur des endroits non isolés de la laveuse à
pression.
11. To reduce the risk of injury, close supervision is
necessary when a machine is used near children.
Do not allow children to operate the pressure
washer. This machine must be attended during
operation.
WARNING: Grip cleaning wand
securely with both hands
before starting. Failure to do
this could result in injury from a
whipping wand.
AVERTISSEMENT : Agripper la
lance de nettoyage avec les
deux mains avant de
commencer. Le non-respect de
cette consigne pourrait mener à
des blessures causées par le
mouvement violent de la lance.
12. Never make adjustments on machine while in
operation.
WARNING
USE
PROTECTIVE
EYEWEAR, GLOVES
AND FOOTWEAR
WHEN OPERATING.
WARNING
EAR PROTECTION
MUST BE WORN
WARNING
HOT DISCHARGE FLUID:
DO NOT TOUCH OR
DIRECT DISCHARGE
STEAM AT PERSONS.
WARNING
RISK OF INJURY.
HOT SURFACES
CAN CAUSE BURNS
WARNING
TRIGGER GUN KICKS
BACK — HOLD WITH
BOTH HANDS
Karcher HDS 505, 508, 509, 510 Operator’s Manual 9.800-078.0 - T
8
Safety
13. Be certain all quick coupler fittings are secured
before using pressure washer.
WARNING: High pressure
developed by these machines
will cause personal injury or
equipment damage. Keep clear
of nozzle. Use caution when
operating. Do not direct
discharge stream at people or
animals, or severe injury or
death will result.
AVERTISSEMENT : La haute
pression générée par ces
machines causera des lésions corporelles ou des
dommages à l'équipement. Se tenir à l'écart de la
buse. Faire preuve de prudence lors de l'utilisation.
Ne pas décharger directement le jet vers des
personnes ou des animaux, car cela risquerait de
causer des blessures graves ou même la mort.
WARNING: Protect machine
from freezing.
AVERTISSEMENT : Protéger la
machine contre le gel.
14.To keep machine in best
operating conditions, it is
important you protect machine
from freezing. Failure to protect
machine from freezing could
cause malfunction of the machine
and result in death, serious bodily injury, and/or
property damage. Follow storage instructions
specified in this manual.
15. Inlet water must be clean fresh water and no hotter
then 90°F.
DANGER: Risk of asphyxiation.
Use this product only in a well
ventilated area.
DANGER : Risque d'asphyxie.
Utiliser ce produit uniquement
dans un endroit bien ventilé.
16.Avoid installing machines in
small areas or near exhaust fans.
Adequate oxygen is needed for
combustion or dangerous carbon
monoxide will result.
17. Manufacturer will not be liable for any changes
made to our standard machines or any compo-
nents not purchased from us.
18. The best insurance against an accident is precau-
tion and knowledge of the machine.
WARNING: Be extremely careful
when using a ladder, scaf-
folding or any other relatively
unstable location. The cleaning
area should have adequate
slopes and drainage to reduce
the possibility of a fall due to
slippery surfaces.
AVERTISSEMENT : Faire
preuve d'une extrême prudence
au moment d'utiliser une
échelle, des échafaudages ou toute autre surface
relativement instable. La zone de nettoyage doit
avoir une pente et un drainage adéquats pour
réduire la possibilité d'une chute due à une surface
glissante.
19. Do not overreach or stand on unstable support.
Keep good footing and balance at all times..Do not
operate this machine when fatigued or under the
influence of alcohol, prescription medications, or
drugs.
WARNING: Do not spray
machine or any people, animals
or electrical parts.
AVERTISSEMENT : Ne pas
vaporiser sur la machine ou les
gens, les animaux ou les pièces
électriques.
WARNING: If connection is
made to a potable water system,
the system shall be protected
against backflow.
AVERTISSEMENT : Si une
connexion est établie avec un
réseau d'eau potable, le réseau
doit être protégé contre le retour
d'eau.
Follow the maintenance
instructions specified in the manual.
WARNING
RISK OF INJECTION
OR SEVERE INJURY
TO PERSONS. KEEP
CLEAR OF NOZZLE.
WARNING
PROCTECT FROM
FREEZING
DANGER
RISK OF
ASPHYXIATION.
USE THIS PRODUCT
ONLY IN A WELL
VENTILATED AREA.
WARNING
RISK OF INJURY
FROM FALLS WHEN
USING LADDER.
WARNING
DO NOT SPRAY
MACHINE OR ANY
PEOPLE, ANIMALS OR
ELECTRICAL PARTS.
WARNING
IF CONNECTED
TO A POTABLE
WATER SUPPLY,
PROTECT AGAINST
BACKFLOW.
Karcher HDS 505, 508, 509, 510 Operator’s Manual 9.800-078.0 - T
9
Operations
Component Identification
CAUTION HOT WATER:
Must use insulated
spray gun and wand.
High Limit
Thermostat
Fuel Tank
Wand Holder
Downstream
Detergent
Injector
Pump
Fresh Water
Faucet
(not included)
Garden Hose
(not included)
High Pressure
Hose
Burner
Motor
Insulated
Spray Gun
Variable Pressure
Insulated Wand
Control
Handle
Detergent
Bucket
(not included)
Detergent
Pick-Up
Hose
Burner
Chamber
Control
Panel
Pump Switch
Burner Switch
Discharge
Nipple
Quick
Coupler
Nozzle
Coupler
Pressure
Switch
Unloader
GFCI
High
Pressure
Nozzle
Karcher HDS 505, 508, 509, 510 Operator’s Manual 9.800-078.0 - T
10
Operations
Assembly Instructions
STEP 1: Connect water supply
hose.
STEP 4: Engage the spray gun
safety latch. Attach the high
pressure hose to the spray gun
using teflon tape on hose threads.
STEP 2: Check fuel tank and pump
oil levels.
STEP 5: Connect the high pressure
nozzle to the wand quick coupler by
sliding coupler collar back. Push
coupler collar forward until secure.
STEP 3: Connect high pressure
hose to discharge nipple by sliding
quick coupler collar back. Insert
quick coupler onto discharge nipple
and secure by pushing quick
coupler collar forward.
98000780-6
Safety
Latch
Fuel
Cap
Karcher HDS 505, 508, 509, 510 Operator’s Manual 9.800-078.0 - T
11
Operations
Installation
Place machine in a convenient location providing
ample support, draining and room for maintenance.
This machine is intended for outdoor use. Machine
must be stored indoors when not in use.
Location
The location should protect the machine from
damaging environmental conditions, such as wind, rain,
and freezing.
1. This machine should be run on a level surface
where it is not readily influenced by outside
sources such as strong winds, freezing tempera-
tures, rain, etc. It should be located to allow acces-
sibility for refilling of fuel, adjustments and
maintenance. Normal precautions should be taken
by the operator of the machine to prevent moisture
from reaching the electrical controls.
2. It is recommended that a partition be made
between the wash area and the machine to
prevent water spray from coming in contact with
the machine. Excess moisture reaching any
electric components or electrical controls will
reduce machine life and may cause electrical
shorts.
3. During installation of the machine, beware of
poorly ventilated locations or areas where exhaust
fans may cause an insufficient supply of oxygen.
Sufficient combustion can only be obtained when
there is a sufficient supply of oxygen available for
the amount of fuel being burned. If it is necessary
to install a machine in a poorly ventilated area,
outside fresh air may have to be piped to the
burner and a fan installed to bring air into the
machine.
Avoid small locations or areas near exhaust fans.
Electrical
This machine, when installed, must be electrically
grounded in accordance to local codes. Check for
proper power supply using a volt meter.
Placement
Do not locate near any combustible material. Keep all
flammable material at least 20 feet away.
Allow enough space for servicing the machine.
Local code will require certain distances from floor and
walls. (Two feet away from walls should be adequate.)
Water Source
The water source for the pressure washer should be
supplied by a minimum 5/8" I.D. garden hose with a city
water pressure of not less than 30 PSI. If the water
supply is inadequate, or if the garden hose is kinked,
the attached pressure washer will run very rough and
the burner will not fire.
Connection
Connect the wand, nozzle, hose and spray gun (where
applicable). On pipe thread connections, use teflon
tape to avoid water leaks. (See Component Identifica-
tion).
Venting
Adding exhaust vent pipe to your oil fired burner is not
recommended because restricted air flow causes
carbon build-up, which affects the operation, and
increases maintenance on the coil. If a stack must be
used, refrain from using 90° bends. If the pipe can not
go straight up then use only 45° bends and go to the
next size pipe. The overall pipe length must not exceed
6 feet in length*.
NOTE: After vent pipe installation test burner using a
smoke tester and adjust air setting to achieve a #3 or
below results.
Karcher HDS 505, 508, 509, 510 Operator’s Manual 9.800-078.0 - T
12
Operations
Operating Instructions
STEP 1: Turn water on.
STEP 4: Before installing nozzle,
turn on water supply and run
machine, allowing water to flush
through the system until clear.
Turn switch to pump position.
When a steady stream of water
flows from the spray gun and wand
the machine is ready for cold water
cleaning by turning the variable
pressure control handle clockwise
to raise the pressure.
For hot water washing, turn the
switch to the burner position. (The
burner will light automatically when
the trigger on the spray gun is
pulled.)
STEP 2: Connect the power cord
into the proper electrical outlet,
then push in the GFCI reset button
if provided. (Refer to serial plate for
information).
STEP 3: Grip spray gun handle
securely and pull trigger. Then turn
variable pressure control handle
counterclockwise.
98000780-8
98000780-11
98000780-9
98000780-12
Variable Pressure
Control Handle
Trigger
Variable Pressure
Wand (VP)
High
Pressure
Nozzle
Brass Soap
Nozzle
Safety
Latch
98000780-10
Karcher HDS 505, 508, 509, 510 Operator’s Manual 9.800-078.0 - T
Selection of high or low pressure is accompanied by turning the handle.
NOTE: High pressure nozzle must be inserted at end of wand to obtain high
pressure. To apply soap read operator's manual.
13
Operations
Detergents & General Operating
Techniques
WARNING: Some detergents
may be harmful if inhaled or
ingested, causing severe
nausea, fainting or poisoning.
The harmful elements may
cause property damage or
severe injury.
STEP 1: Connect detergent
injector to discharge nipple on
machine, Connect high pressure
hose to injector with quick coupler
(check to make sure locking coupler sleeves are in
proper position before applying water pressure.
STEP 2: Use detergent designed
specifically for pressure washers.
Household detergents could damage
the pump. Prepare detergent solution
as required by the manufacturer. Fill a
container with pressure washer
detergent. Place the filter end of
detergent suction tube into the
detergent container.
STEP 3: Apply safety latch to spray gun trigger. Turn
variable pressure control handle until discharge water
exits both tubes. Secure black detergent nozzle into
quick coupler if you have a single wand. NOTE:
Detergent cannot be applied using Red, Yellow, Green
or White nozzles.
STEP 4: With the engine running,
pull trigger to operate machine.
Liquid detergent is drawn into the
machine and mixed with water.
Apply detergent to work area. Do
not allow detergent to dry on
surface.
Thermal Pump Protection
If you run the engine on your pressure washer for 3-5
minutes without pressing the trigger on the spray gun,
circulating water in the pump can reach high tempera-
tures. When the water reaches this temperature, the
pump protector engages and cools the pump by
discharging the warm water onto the ground. This
thermal device prevents internal damage to the pump.
Cleaning Tips
Pre-rinse cleaning surface with fresh water. Place
detergent suction tube directly into cleaning solution
and apply to surface at low pressure (for best results,
limit your work area to sections approximately 6 feet
square and always apply detergent from bottom to top).
Allow detergent to remain on surface 1-3 minutes. Do
not allow detergent to dry on surface. If surface
appears to be drying, simply wet down surface with
fresh water. If needed, use brush to remove stubborn
dirt. Rinse at high pressure from top to bottom in an
even sweeping motion keeping the spray nozzle
approximately 1 foot from cleaning surface. Use over-
lapping strokes as you clean and rinse any surface. For
best surface cleaning action spray at a slight angle.
Recommendations
• Before cleaning any surface, an inconspicuous
area should be cleaned to test spray pattern
and distance for maximum cleaning results.
• If painted surfaces are peeling or chipping, use
extreme caution as pressure washer may
remove the loose paint from the surface.
• Keep the spray nozzle a safe distance from the
surface you plan to clean. High pressure wash
a small area, then check the surface for
damage. If no damage is found, continue to
pressure washing.
CAUTION - Never use:
• Bleach, chlorine and other corrosive chemicals
• Liquids containing solvents (i.e., paint thinner,
gasoline, oils)
• Tri-sodium phosphate products
• Ammonia products
• Acid-based products
These chemicals will harm the machine and will
damage the surface being cleaned.
Rinsing
It will take a few seconds for the detergent to clear.
Apply safety latch to spray gun. Remove black soap
nozzle from the quick coupler. Select and install the
desired high pressure nozzle. NOTE: You can also stop
detergent from flowing by simply removing detergent
siphon tube from bottle.
WARNING
98000780-13
98000780-14
98000780-15
Karcher HDS 505, 508, 509, 510 Operator’s Manual 9.800-078.0 - T
14
Operations
Shutting Down And
Clean-Up
STEP 1: Remove detergent suction
tube from container and insert into
1 gallon of fresh water. Turn
variable pressure wand handle for
low pressure or connect the black
detergent nozzle. Pull trigger on
spray gun and siphon water for one
minute.
STEP 4: Turn garden hose water
off. Open the spray gun to relieve
remaining pressure.
STEP 2: Turn burner switch off and
continue spraying water, allowing
the water to cool. After water has
cooled to less than 100°F, turn the
attached pressure washer off.
STEP 3: Turn off water supply.
Karcher HDS 505, 508, 509, 510 Operator’s Manual 9.800-078.0 - T
15
Operations
Storage
CAUTION: Always store your pressure washer in a
location where the temperature will not fall below
32°F (0°C). The pump in this machine is susceptible
to permanent damage if frozen. FREEZE DAMAGE
IS NOT COVERED BY WARRANTY.
Attention : Toujours entreposer la laveuse à
pression dans un endroit où la température ne sera
pas inférieure à 0 °C (32 °F). La pompe sur cette
machine est susceptible de subir des dommages si
elle est exposée au gel. LES DOMMAGES DUS AU
GEL NE SONT PAS COUVERTS PAR LA GARANTIE.
1. Stop the pressure washer, squeeze spray gun
trigger to release pressure.
2. Detach water supply hose and high pressure hose.
3. Turn on the machine for a few seconds, until
remaining water exits. Turn motor off immediately.
4. Drain the fuel from the fuel tank.
5. Do not allow high pressure hose to become kinked.
6. Store the machine and accessories in a room
which does not reach freezing temperatures.
CAUTION: Failure to follow the above directions
will result in damage to your pressure washer.
Attention : Le non-respect des directives ci-dessus
entraînera des dommages à la laveuse à pression.
When the pressure washer is not being operated or is
being stored for more than one month, follow these
instructions:
1. Replenish pump oil to upper level.
2. Drain fuel from fuel tank, fuel line and filter.
3. Cover the pressure washer and store in a clean,
dry place that is well ventilated away from open
flame or sparks.
After Extended Storage
CAUTION: Prior to restarting, thaw out any
possible ice from pressure washer hoses,
spray gun or wand.
Attention : Avant de redémarrer, faire fondre la
glace se trouvant sur les boyaux, le pistolet pulvéri-
sateur ou la lance de la laveuse à pression.
Karcher HDS 505, 508, 509, 510 Operator’s Manual 9.800-078.0 - T
16
Maintenance
Preventative Maintenance
1. Use clean fuel — kerosene, No. 1 home heating
fuel or diesel fuel. Clean or replace fuel filter every
100 hours of operation. Avoid water contaminated
fuel as it will seize up the fuel pump. De-soot coils
monthly. Use an additive if diesel is being used.
2. Check to see that the attached pressure washer
water pump is properly lubricated.
3. Follow winterizing instructions to prevent freeze
damage to pump and coils.
4. Always neutralize and flush detergent from system
after use.
5. If water is known to be high in mineral content, use
a water softener on your water system, or de-scale
as needed.
6. Do not allow acidic, caustic or abrasive fluids to be
pumped through the system.
7. Always use high grade quality cleaning products.
8. Never run attached pressure washer pump dry for
extended periods of time.
9. If machine is operated with smoky or eye burning
exhaust, coils will soot up, preventing water from
reaching maximum operating temperature. (See
section on Maintenance and Service).
10. Never allow water to be sprayed on or near the
motor or burner assembly or any electrical compo-
nent.
11. Descale coils as per instructions.
It is advisable, periodically, to visually inspect the
burner. Check air inlet to make sure it is not clogged or
blocked. Wipe off any oil spills and keep equipment
clean and dry.
The areas around the pressure washer should be kept
clean and free of combustible materials, gasoline and
other flammable vapors and liquids.
The flow of ventilating air to the burner must not be
blocked or obstructed in any manner.
Maintenance And Service
Unloader Valves
Unloader valves trap pressure in the line when a shut-
off spray gun is closed. Machines with unloader valves
are preset and tested at the factory before shipping.
Tampering with the factory settings may cause
personal injury and/or property damage and will void
the manufacturer's warranty.
Winterizing Procedure
Damage due to freezing is not covered by warranty.
Adhere to the following cold weather procedures
whenever the washer must be stored or operated
outdoors under freezing conditions.
During winter months, when temperatures drop below
32°F, protecting your machine against freezing is
necessary. Store the machine in a heated room. If this
is not possible then mix a 50/50 solution of anti-freeze/
water or windshield washer fluid with water in a 5 gallon
bucket. Place a short section of garden hose into the
bucket and connect it to the machine. Elevate the
bucket and turn the pump on to siphon the anti-freeze
through the machine. If compressed air is available, an
air fitting can be screwed into the inlet connector and by
injecting compressed air, all water will be blown out of
the system.
If you have an optional float tank, pour the antifreeze
into this tank and run machine until antifreeze exits
discharge nipple.
High Limit Hot Water Thermostat
For safety, each machine is equipped with a high limit
control switch. In the event the temperature of the water
should exceed its operating temperature, the high limit
control will turn the burner off until the water cools.
Pumps
Use only SAE 10W-40 weight non-foaming oil. Change
oil after first 50 hours of use. Thereafter, change oil
every year or at 500 hour intervals. Oil level should be
checked by using the dipstick found on the top of the
pump or by the red dot visible through the oil gauge
window. Oil should be maintained at that level.
Karcher HDS 505, 508, 509, 510 Operator’s Manual 9.800-078.0 - T
17
Maintenance
Cleaning of Coils
In alkaline water areas, lime deposits can accumulate
rapidly inside the coil pipes. This growth is increased by
the extreme heat build up in the coil. The best preven-
tion for liming conditions is to use high quality cleaning
detergents. In areas where alkaline water is an extreme
problem, periodic use of Karcher Coil Descaler (part #
9.803-742.0) will remove lime and other deposits
before coil becomes plugged.
Periodic descaling of the heating coil is recommended
so please consult your local Karcher Dealer for instruc-
tions
Removal of Soot In Heating Coil
In the heating process, fuel residue in the form of soot
deposits may develop between the heating coil pipe
and block air flow which will affect burner combustion.
When soot has been detected on visual observation,
the soot on the coil must be washed off after coil has
been removed using the following steps:
1. Remove the tank head assembly by unscrewing
the three tek screws and lifting the tank head off.
2. Remove the two pipe nipples and associated
fittings.
3. Lift the coil out of the outer wrap.
CAUTION: The coil weighs about 80 lbs. Use proper
lifting techniques.
Attention : La bobine pèse environ 36.25kg (80 lb).
Utiliser des techniques de levage appropriées.
4. Clean, repair and replace the coil by reversing the
above steps.
Coil Re-installation
Reinstall by reversing the above steps 4 through 1.
Rupture Disk
If pressure from pump or thermal expansion should
exceed safe limits, the rupture disk will burst, allowing
high pressure to be discharged through hose to ground.
When the disk ruptures, it will need to be replaced.
Fuel
Use clean fuel oil that is not contaminated with water
and debris. Replace fuel filter and drain tank every 100
hours of operation. Use Kerosene No. 1 or No. 2
Heating Fuel (ASTM D306) or diesel only. NEVER use
gasoline in your burner tank. Gasoline is more combus-
tible than fuel oil and could result in a serious explo-
sion. NEVER use crankcase or waste oil in your burner.
Fuel unit malfunction could result from contamination.
Ignition Circuit
Periodically inspect wires, spring contact and elec-
trodes for condition, security and proper spacing. For
transformer test (CAUTION 10,000 VOLTS) use
defect free insulated screwdriver and keep fingers off
blade! Lay blade across one contact: OK if arc will
span 1/2" between end of blade and other contact.
Karcher HDS 505, 508, 509, 510 Operator’s Manual 9.800-078.0 - T
18
Maintenance
Electrode
Setting
SR-Series Gage
KNA Part Number: 8.717-379.0
Burner Nozzle
Keep the tip free of surface deposits by wiping it with a
clean, solvent-saturated cloth, being careful not to plug
or enlarge the nozzle. For maximum efficiency, replace
the nozzle each season.
Fuel Control System
This machine utilizes a fuel solenoid valve located on
the fuel pump to control the flow of fuel to the combus-
tion chamber. This solenoid is activated by a pressure
switch located on the unloader valve. When an
operator releases the trigger on the spray gun, the
pressure drops, allowing the pressure switch to activate
the fuel solenoid. The solenoid then closes, shutting off
the supply of fuel to the combustion chamber.
Controlling the flow of fuel in this way gives an instanta-
neous burn or no burn situation, thereby eliminating
high and low water temperatures, and combustion
smoke normally associated with machines incorpo-
rating a spray gun. Periodic inspection is recom-
mended to insure that the fuel solenoid valve functions
properly. This can be done by operating the machine
and checking to see that when the trigger on the spray
gun is in the off position, the burner is not firing.
Fuel Pressure Adjustment
To adjust fuel pressure, First install a pressure gage
into the port just after the pump fuel exit. Turn the
adjusting screw (located at the regulator port)
clockwise to increase, and counterclockwise to
decrease. Do not exceed 200 psi or lower the pressure
below 130 PSI, when checked at the post-pump
pressure port.
The fuel pressure may need to be adjusted due to
altitude. For every 500 ft altitude above sea level, the
boiling point of water goes down 1 °F. At high altitude
environments, this boiling point change may require the
heat input to be lowered so the water input does not
turn to steam earlier than at the factory settings and
activate the pressure sensors and pressure relief
equipment when the unit is operated and much higher
altitudes from factory settings or local dealer site
settings. Check with your dealer before making local
site fuel pressure adjustments.
Also, as ambient temperature changes seasonally, the
fuel temperature in the feed tank and air temperature
inlet can impact fuel flow. In more extreme tempera-
tures, this local-site adjustment may also require
different fuel nozzles for fuel inlet temperatures that are
at seasonal extremes (higher or lower) in locations
where the temperature changes are beyond moderate
temperatures of between 40°F and 90°F. Colder
temperatures will make for a thicker flow and less fine a
fuel spray while hotter temperatures will make for a
thinner flow a more fine spray with the same nozzle.
Consider alternate nozzle configurations from the
baseline factory-supplied nozzle for operating in such
temperature extremes if performance is not meeting
needs with air band and fuel pressure settings alone.
NOTE: When changing fuel pump, a by-pass plug
must be installed in return line port or fuel pump will
not prime.
Karcher HDS 505, 508, 509, 510 Operator’s Manual 9.800-078.0 - T
19
Maintenance
Oil Burner
Burner Air Adjustment: The oil burner on this
machine is preset for operation at altitudes below 500
feet. If operated at higher altitudes, it may be necessary
to adjust the air band for a #1 or #2 smoke spot on the
Bacharach scale.
To adjust, start machine and turn burner ON. Loosen
two locking screws found on the air band and close air
band until black smoke appears from burner exhaust
vent. Note air band position. Next, slowly open the air
band until white smoke just starts to appear. Turn air
band halfway back to the previously noted position.
Tighten locking screws.
For higher altitudes, the air band opening may need to
be increased; for lower altitude, the .air band may need
to be decreased.
For higher humidity, the air band opening may need to
be increased; for lower relative humidity, the .air band
may need to be decreased.
For higher ambient temperatures the air band opening
may need to be increased; for lower ambient tempera-
tures, the air band opening may need to be decreased.
Adjust to your operating location's environment as-
needed for best smoke spot and performance
compliant with local, state, and federal regulations.
CAUTION: If white smoke appears from burner exhaust
vent during start-up or operation, discontinue use and
readjust air bands.
NOTE: If a flue is installed, have a professional
serviceman adjust your burner for a #1 or #2 smoke
spot on the Bacharach scale.
Karcher HDS 505, 508, 509, 510 Operator’s Manual 9.800-078.0 - T
20
Maintenance
Maintenance Charts
This pressure washer was produced with the best
available materials and quality craftsmanship.
However, you as the owner have certain responsibili-
ties for the correct care of the equipment. Attention to
regular preventative maintenance procedures will
assist in preserving the performance of your equip-
ment. Contact your Pressure Washers dealer for main-
tenance. Regular preventative maintenance will add
many hours to the life of your pressure washer. Perform
maintenance more often under severe conditions.
Oil Change Record
MAINTENANCE SCHEDULE
Replace Fuel Lines Annually
Pump Oil (non-foaming
SAE 10W-40)
Inspect Daily inspect the oil level
Change After first 50 hours, then every 500 hours or annually
Clean Burner Filter Monthly (More often if fuel quality is poor)
Remove Burner Soot Annually
Burner Adjustment/Cleaning Annually
De-scale Coil Annually (More often if required)
Replace High Pressure Nozzle Every 6 months
Replace Quick Connects Annually
Clean Water Screen/Filter Weekly
Clean Float/Supply Tank Every 6 months
Replace HP Hose Annually if there is any sign of wear
Grease Motor Every 10,000 hours
Replace Burner Nozzle Annually
D a t e O i l C h an ge d
Month/Day/Year
Estimated Operating
Hours Since Last Oil
Change
D a t e O i l C h an ge d
Month/Day/Year
Estimated Operating
Hours Since Last Oil
Change
Karcher HDS 505, 508, 509, 510 Operator’s Manual 9.800-078.0 - T
21
Maintenance
Troubleshooting
PROBLEM POSSIBLE CAUSE SOLUTION
LOW
OPERATING
PRESSURE
Faulty pressure gauge Install new gauge.
Insufficient water supply
Use larger garden hose; clean filter washer at water
inlet.
Old, worn or incorrect spray
nozzle
Match nozzle number to machine and/or replace with
new nozzle.
Plumbing or hose leak
Check plumbing system for leaks. Retape leaks with
teflon tape.
Faulty or mis-adjusted unloader valve
(where applicable)
Adjust unloader for proper pressure. Install repair kit
when needed.
Worn packing in pump Install new packing kit.
Fouled or dirty inlet or discharge
valves in pump
Clean inlet or discharge valves.
Worn inlet or discharge valves Replace with valve kit.
DETERGENT
NOT
DRAWING
Air leak Tighten all clamps. Check detergent lines for holes.
Valve in the injector head may
be blocked, dirty or damaged
Clean or replace valve in injector.
Filler screen on detergent suction
hose plugged
Clean or replace.
Dried up detergent plugging
metering valve
Disassemble and clean thoroughly.
High viscosity of detergent Dilute detergent to specifications.
Hole in detergent line(s) Repair hole.
Low detergent level Add detergent if needed.
Discharge water temperature above
180°F
Lower discharge water temperature.
PUMP RUNNING
NORMALLY BUT
PRESSURE LOW
ON INSTALLATION
Pump sucking air Check water supply and possibility of air seepage.
Valves sticking Check and clean or replace if necessary.
Unloader valve seat faulty Check and replace if necessary.
Nozzle incorrectly sized
Check and replace if necessary
(See serial plate for proper size).
Worn piston packing Check and replace in necessary.
FLUCTUATING
PRESSURE
Valves worn Check and replace if necessary.
Blockage in valve Check and replace if necessary.
Pump sucking air
Check water supply and air seepage
at joints in suction line.
Worn piston packing Check and replace if necessary.
PUMP
NOISY
Air in suction line Check water supply and connections on suction line.
Broken or weak inlet or discharge
valve springs
Check and replace if necessary.
Excessive matter in valves Check and clean if necessary.
Worn bearings Check and replace if necessary.
Karcher HDS 505, 508, 509, 510 Operator’s Manual 9.800-078.0 - T
22
Maintenance
Troubleshooting
PROBLEM POSSIBLE CAUSE SOLUTION
LOW WATER
TEMPERATURE
Improper fuel or water in fuel Drain fuel tank and replace with proper fuel.
Low fuel pressure Increase fuel pressure.
Weak fuel pump Check fuel pump temperature. Replace pump if needed.
Fuel filter partially clogged Replace as needed.
Soot build up on coils Clean coils with soot remover.
Lime build up on coils Clean inside of coils using coil cleaner.
Improper burner nozzle See Burner Specifications.
WATER
TEMPERATURE
TOO HOT
Incoming water to machine
warm or hot
Lower incoming water temperature.
Fuel pump pressure too high Lower fuel pressure.
Fuel pump defective Replace fuel pump.
Detergent line sucking air Tighten all clamps. Check detergent line for holes.
Defective high limit switch
(thermostat)
Replace.
Incorrect fuel nozzle size See Burner Specifications.
Insufficient water supplied Check GPM to machine.
Restricted water flow Check nozzle for obstruction, proper size.
MACHINE
SMOKES
WHILE
BURNER UNIT
IS RUNNING
OR
UNIT SMOKES AT
COLD-START
ONLY WHEN
BURNER
IS OFF
Improper air adjustment Readjust air bands on burner assembly
Fuel pressure is low <140 psi for
burner
Adjust fuel pump pressure to specifications
Burner nozzle is plugged or dirty Replace nozzle. Check parts breakdown for nozzle size
Burner nozzle spray pattern is faulty Replace nozzle. Check parts breakdown for nozzle size
Heavy accumulation of soot on coils
and burner assembly
Remove coils and burner assembly, clean thoroughly.
Call local dealer
Misaligned electrode setting Realign electrodes to specifications
Obstruction in smoke stack Check for insulation blockage or other foreign objects
Low engine RPM Increase RPM to correct specs. See serial plate
Fuel Pressure is too high for clean
burn (fuel PSI above 140 and below
200) and smokes when burner is off
Reduce fuel pressure PSI/Increase air band set for
cleaner without max water heat loss
Karcher HDS 505, 508, 509, 510 Operator’s Manual 9.800-078.0 - T
9.800-078.0 • Printed in U.S.A.
