Kärcher HPB Series Operator's Manual page 18

Maintenance
Deliming Coils With A Pressure Washer:
Periodic flushing of coils is recommended.
1. Fill a 5 gallon bucket with 4 gallons of water, then
add 1 lb. of deliming powder. Mix thoroughly.
2. Remove the high pressure nozzle from the
pressure wand and put the wand into the bucket.
Secure the trigger on the spray gun into the open
position.
3. Attach a short section (3-5 ft.) of garden hose to
the attached pressure washer to siphon solution
from the elevated bucket. Start up pressure
washer, allowing solution to be pumped through
pressure washer and into HPB coils and back into
the bucket. Solution should be allowed to circulate
2-4 hours.
4. After circulating solution flush entire system with
fresh water.
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 36.3
kg (80 lb). Utiliser des techniques de
levage appropriées.
4. Clean, repair and replace the coil by reversing the
above steps.
Coil Reinstallation
Reinstall by reversing the above steps 4 through 1.
18 Kärcher HPB Series Operator's Manual 9.801-190.0 - W
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.
Electrode Setting: