20
Maintenance
Troubleshooting
PROBLEM
POSSIBLE CAUSE
SOLUTION
LOW
OPERATING
PRESSURE
Faulty pressure gauge
Install new gauge.
Insufficient water supply
Use larger supply hose; clean filter at water
inlet.
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 mis-adjusted
unloader valve
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 and discharge valves.
Worn inlet or discharge valves
Replace with valve kit.
Obstruction in spray nozzle
Remove obstruction.
Leaking pressure control valve
Rebuild or replace as needed.
Slow engine RPM
Set engine speed at proper specifications.
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.
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.
Clogged fuel line
Clean or replace.
Plugged fuel filter
Replace as needed.
Mis-adjusted burner air bands
Readjust air bands for clean burn.
Little or no fuel pressure from fuel pump
Increase fuel pressure to specification and/or
replace fuel pump. Test with pressure gauge.
Faulty burner transformer
Test transformer for proper arc between
contacts. Replace as needed.
(continued on next
page)
Disconnected or short in electrical
wiring
All wire contacts should be clean and tight. No
breaks in wire
Karcher HDS 615-617 Operator’s Manual 9.800-103.0 - V
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