Karcher • HDS 650 • 9.800-081.0 • Rev. 5/10a
11
PRESSURE WASHER Troubleshooting Guide
TROUBLESHOOTING
PROBLEM
POSSIBLE CAUSE
SOLUTION
BURNER WILL NOT
LIGHT
Disconnected or short in electrical
wiring
All wire contacts should be clean and
tight. No breaks in wire.
Burner motor thermal protector tripped If tripped, check voltage, connections and
extensions for cause. Check fuel pump
shaft rotation for binding, causing motor to
overheat.
On/off switch defective
Check continuity through burner switch.
Heavy sooting on coil and burner,
can cause interruption of air flow and
shorting of electrodes
Clean as required.
Improper electrode setting
Clean and test according to diagram in
operator's manual.
Fuel not reaching combustion chamber Check fuel pump for proper flow. Check
solenoid flow switch on machines with
spray gun control for proper ON/OFF flow
switch.
Fuel solenoid malfunction
Check by placing screwdriver inside coil
then turn machine on, open spray gun
and check for magnetic pull.
Clogged burner nozzle
Replace.
Water not turned on
Turn on water to activate burner flow
switch.
Flow switch malfunction
Remove, test for continuity and replace as
needed.
MACHINE SMOKES
Improper fuel or water in fuel
Drain tank and replace contaminated fuel.
Low fuel pressure
Adjust fuel pump pressure to specifica-
tions.
Air leaks in fuel lines
Check fuel lines for leaks or air bubbles.
Tighten or replace as needed.
Plugged or dirty burner nozzle
Replace.
Faulty burner nozzle spray pattern
Replace nozzle.
Heavy accumulation of soot on coils
and burner assembly
Remove coils and burner assembly. Clean
thoroughly.
Misaligned electrode
Realign electrodes to specifications.
Fuel filter partially clogged
Replace as needed.
Obstruction in smoke stack
Check for insulation blockage or other
foreign objects.
Soot build-up on coils
Clean coils with soot remover.
Lime build-up in coils
Clean inside of coils using coil cleaner.
Summary of Contents for HDS 5.0/30 Ed
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