9.800-103.0 - M • Karcher HDS 615-617
OPERA
T
OR’S MANU
AL
PRESSURE W
ASHER
14
MAINTENANCE & SERVICE
When operating unit without a scale protection,
the heater coil may become scaled.
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.
Fuel:
Use clean fuel oil that is not contaminated with water
and debris. Replace fuel fi lter and drain tank every 100
hours of operation.
Use No.1 or No 2 Heating Oil (ASTM D306) only.
NEV ER use gasoline in your burner fuel tank. Gas o line
is more combustible than fuel oil and could result in a
serious ex plo sion.
NEVER
use crankcase or waste oil
in your burn er. Fuel unit malfunction could result from
contamination.
CAUTION: If the fuel pump is allowed to run dry for
any length of time it will be damaged.
Fuel Control System:
This machine utilizes a fuel solenoid valve located on
the fuel pump to control the fl ow of fuel to the com bus -
tion cham ber. The solenoid, which is normally closed,
is activated by a fl ow switch when water fl ows through
it. When the op er a tor releases the trigger on the spray
gun, the fl ow of water through the fl ow switch stops,
turning off the electrical cur rent to the fuel solenoid.
The solenoid then closes, shutting off the supply of
fuel to the combustion chamber. Controlling the fl ow
of fuel in this way gives an instantaneous burn-or-no-
burn sit u a tion, there by eliminating high and low water
tem per a tures and the combustion smoke normally
associated with ma chines in cor po rat ing a spray gun.
Periodic in spec tion, to insure that the fuel solenoid
valve func tions properly, is rec om mend ed. This can
be done by op er at ing the ma chine and checking to
see that the burner is not fi ring when the spray gun is
in the OFF position.
When operating without the burner there must be heat-
ing fuel in the fuel tank. Otherwise the fuel pump has
no lubrication and will run dry. This can cause damage
to the coupling and to the fuel pump.
Fuel Pressure Adjustment:
To control water temperature, adjust fuel pressure by
turn ing the regulating pressure adjusting screw clock-
wise to in crease, counterclockwise to decrease. Do not
exceed 200 psi.
NOTE
: When changing fuel pump,
a by pass plug must be installed in return port or fuel
pump will not prime.
Burner Nozzle:
Keep the tip free of surface deposits by wiping it with
a clean, solvent saturated cloth, being careful not to
plug or enlarge the nozzle. For maximum effi ciency,
re place the nozzle each season.
Air Adjustment:
Machines are preset and performance tested at the
fac to ry - el e va tion 100'. A one-time initial correction for
your lo ca tion will pay off in economy, performance, and
ex tend ed ser vice life. If a smoky or eye-burning exhaust
is being emit ted from the stack, two things should be
checked. First, check the fuel to be certain that ker o sene
or No. 1 home heating fuel is being used. Next, check the
air adjustment on the blower assembly.
