19
Maintenance
PROBLEM
POSSIBLE CAUSE
SOLUTION
WATER ESCAPING FROM
FILL PIPE ON HEAT
EXCHANGER
Cold water added to heat exchanger
Will stop once at operating temperature.
Ruptured coil or leaking
Check, repair or replace fittings.
UNLOADER DOES NOT GO
INTO BYPASS OR WILL
CYCLE ITSELF
Spray gun or hose is leaking to atmo-
sphere
Check and repair all leaks.
Check plunger either did not move or
did not seal
Remove discharge port. Clean and
inspect the check plunger. Replace the o-
ring if needed.
Actuator o-ring failure
Remove actuator plunger assembly and
inspect o-ring and back-up rings.
Replace if necessary.
SPIKES TOO HIGH
Slow moving actuator; this may be
caused by bad o-rings either on the
plunger or inside the actuator fitting.
Remove the actuator assembly to
inspect the o-ring and back-up rings. The
actuator assembly will have to be disas-
sembled to inspect and/or replace the o-
rings in the actuator fitting.
Spring tension
Adjustment should stop when pressure is
no longer affected by further compres-
sion of the spring.
Hose length
Hose length can affect the amount of
spike pressure. Long lengths of hose
may cause high spike pressures.
SYSTEM WON’T COME UP
TO PRESSURE
Water is leaking between ball and seat
Disassemble inlet fitting and check for
contaminates or worn parts. Clean or
replace as needed.
O-Rings on actuator plunger are bad
Remove actuator assembly and inspect
o-ring and back-up rings. Replace if
necessary.
Locknut may be improperly set
Readjust locknut.
NOTE:
The locknut is inside the spring
on models that have the stem exposed
above the spring.
Tip/GPM combination is incorrect
Check actual GPM on unrestricted pump
and size tip accordingly.
Tip worn- the GPM may be greater
than expected with a worn tip
Replace tip.
Bad gauge - the pressure may be
higher than the gauge shows
Replace gauge.
Karcher HDS Series Operator’s Manual 9.800-967.0 - C
