Cleaning Of Coils; Rupture Disk; Fuel; Ignition Circuit - Kärcher HDS 3.9/20 Ea Cage Operator's Manual

Cleaning of Coils

In alkaline water areas, lime deposits can accumulate
rapidly inside the coil pipes. This growth is increased by
the extreme heat build up in the coil. The best preven-
tion for liming conditions is to use high quality cleaning
detergents. In areas where alkaline water is an extreme
problem, periodic use of Karcher Coil Descaler (part #
9.803-742.0) will remove lime and other deposits
before coil becomes plugged.
Periodic descaling of the heating coil is recommended
so please consult your local Karcher Dealer for instruc-
tions
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 36.25kg (80 lb).
Utiliser des techniques de levage appropriées.
4. Clean, repair and replace the coil by reversing the
above steps.
Karcher HDS 505, 508, 509, 510 Operator's Manual 9.800-078.0 - R
Coil Re-installation
Reinstall by reversing the above steps 4 through 1.

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.
Maintenance
17