620-622 • 9.800-187.0 • Rev. 9/10
PRESSURE WASHER Troubleshooting Guide
14
TROUBLESHOOTING
PROBLEM
POSSIBLE CAUSE
SOLUTION
LOW OPERATING
PRESSURE
Faulty pressure gauge
Test with 2nd gauge. If bad install new gauge.
Insufficient water supply
Use larger garden hose; clean water filter at inlet. Clean
screen inside float tank.
Old, worn or incorrect spray nozzle
Match nozzle number to machine and/or replace with
new nozzle.
Belt slippage
Tighten or replace; use correct belt.
Plumbing or hose leak
Check plumbing system for leaks. Retape leaks with
teflon tape.
Faulty or misadjusted unloader valve
(Where applicable)
Adjust unloader for proper pressure. Install repair kit
when needed. Test PSI with unloader removed, taking
pressure directly off the pump.
Worn packing in pump
Install new packing kit.
Fouled or dirty inlet or discharge valves
in pump
Clean inlet and discharge valves.
Worn inlet or discharge valves
Replace with valve kit.
Low power supply
Check voltage of building and compare with require-
ments. Obtain a different power source.
Detergent metering valve left open suck-
ing air, or faulty metering valve
Close and/or replace metering valve.
BURNER WILL
NOT LIGHT
Little or no fuel
Fill tank with fuel.
Improper fuel or water in fuel
Drain fuel tank and fill with proper fuel.
Plugged fuel filter
Replace as needed.
Misadjusted burner air bands
Readjust air bands for clean burn.
Little or no fuel pressure from fuel
pump
Increase fuel pressure to specification on fuel pump
and/or replace fuel pump.
Faulty burner transformer
Test transformer for proper arc between contacts. Re-
place as needed.
Disconnected or short in electrical wir-
ing
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.
Flex-coupling slipping on fuel pump shaft
or burner motor shaft
Replace if needed.
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 set according to diagram in Operators
Manual.
Fuel not reaching combustion chamber
Check fuel pump for proper flow. Check solenoid flow
switch on units with spray gun control, for proper on-off
fuel flow control.
Clogged burner nozzle
Replace.
Water not flowing through unloader
Open spray gun to allow water to flow.
Flow switch malfunction
Remove test for continuity and replace as needed.
Fuel solenoid malfunction
Replace if needed.
