Maintenance And Service; Unloader Valves; Winterizing Procedure; High Limit Hot Water Thermostat - Kärcher HDS Series Operator's Manual

It is advisable, periodically, to visually inspect the
burner. Check air inlet to make sure it is not clogged or
blocked. Wipe off any oil spills and keep equipment
clean and dry.
The flow of combustion and ventilating air to the burner
must not be blocked or obstructed in any manner.
The area around the pressure washer should be kept
clean and free of combustible materials, gasoline and
other flammable vapors and liquids.

Maintenance And Service

Unloader Valves

Unloader valves are preset and tested at the factory
before shipping. Occasional adjustment of the unloader
may be necessary to maintain correct pressure.
Adjusting Unloader Valves
Tampering with the factory setting may cause
personal injury and/or property damage and will void
the manufacturer's warranty.

Winterizing Procedure

Damage due to freezing is not covered by warranty.
Adhere to the following cold weather procedures
whenever the washer must be stored or operated
outdoors under freezing conditions.
During winter months, when temperatures drop below
32°F, protecting your machine against freezing is
necessary. Store the machine in a heated room. If this
is not possible then mix a 50/50 solution of anti-freeze
and water in the float tank. Turn the engine on to siphon
the anti-freeze mixture through the machine. If
compressed air is available, an air fitting can be
screwed into the float tank by removing the float tank
strainer and fitting. Then inject the compressed air.
Water will be blown out of the machine when the trigger
on the spray gun is opened.

High Limit Hot Water Thermostat

For safety, each machine is equipped with a tempera-
ture sensitive high limit control switch. In the event that
the water should exceed its operating temperature, the
high limit control will turn the burner off until the water
cools then it will automatically reset itself. The thermo-
stat sensor is located on the discharge side of the
heating coil. The thermostat control dial is located on
the control panel.
9.808-341.0 - E - Operator's Manual, LFT

Pumps

Before running the pump check the pump crankcase for
a proper oil level. A proper oil level is indicated by the
red dot in the sightglass or between the high and low
marks on the dipstick. Use only SAE 10W-40 non-
foaming oil. Change the initial oil after the first 50 hours
and then change the oil every 500 hours or every year.
When draining oil, clean inside of crankcase to remove
all impurities.
CAUTION: When operating in damp places or with
high temperature fluctuations oil must be changed
immediately.
ATTENTION: Lorsque l'appareil est utilisé dans des
endroits humides ou où les températures fluctuent
fortement, l'huile doit être changée
immédiatement.

Cleaning of Coils

In alkaline water areas, lime deposits can accumulate
rapidly inside the heating coil. This growth is increased
by the extreme heat build up in the coil. The best
preventative for liming conditions is to use high quality
cleaning detergents. In areas where alkaline water is
an extreme problem, periodic use of Kärcher Coil
Descaler (part #9.803-742.0) will remove lime and
other deposits before coil becomes plugged.
Periodic descaling of the heating coil is recom-
mended so please consult your local Kärcher
dealer for instructions.
Removal of Soot from 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 following
the coil removal steps (See Coil Removal section).

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 disk ruptures it will need to be replaced.he
Rupture Disk should be replaced every two years.
Maintenance
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