Hotsy HSS • #8.914-412.0 • Rev. 10/11
15
PRESSURE
W
ASHER
OPERA
TOR’S MANU
AL
MAINTENANCE
Removal of Soot from Heating Coil:
In the heating process, fuel residue in the form of soot
deposits may develop between the heating coil pipes,
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 on page 14).
Relief Valve
WARNING: The relief valve on this pressure washer
has been factory set and sealed and is a field non-
adjustable part. Tampering with the factory setting
may cause personal injury and/or property dam-
age and will void the manufacturer warranty. For
replacement parts refer to coil outlet assembly
exploded views.
Fuel:
Use clean fuel oil that is not contaminated with water
and debris. Replace fuel filter and drain the tank every
100 hours of operation.
Use No.1 or No 2 Heating Oil (ASTM D306) only.
NEVER use gasoline in your fuel tank. Gasoline is
more combustible than fuel oil and could result in a
serious explosion.
NEVER use crankcase or waste oil
in your burner. Fuel unit malfunction could result from
contamination.
Fuel Control System:
This machine utilizes a fuel solenoid valve located on
the fuel pump to control the flow of fuel to the combus-
tion chamber. The solenoid, which is normally closed,
is activated by a flow switch when water flows through
it. When the operator releases the trigger on the spray
gun, the flow of water through the flow switch stops,
turning off the electrical current to the fuel solenoid.
The solenoid then closes, shutting off the supply of
fuel to the combustion chamber. Controlling the flow
of fuel in this way gives an instantaneous burn-or-no-
burn situation, thereby eliminating high and low water
temperatures and the combustion smoke normally
associated with machines incorporating a spray gun.
Periodic inspection, to insure that the fuel solenoid
valve functions properly, is recommended. This can be
done by operating the machine and checking to see
that the burner is not firing when the spray gun is in
the OFF position.
Fuel Pressure Adjustment:
To control water temperature, adjust fuel pressure by
turning the regulating pressure adjusting screw clock-
wise to increase, counterclockwise to decrease. Do not
exceed 200 psi.
NOTE: When changing fuel pump,
a bypass 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 efficiency, replace
the nozzle each season.
Air Adjustment:
Machines are preset and performance tested at the
factory. A one-time initial correction for your location
will pay off in economy, performance, and extended
service life. If a smoky or eye-burning exhaust is being
emitted from the stack, two things should be checked.
First, check the fuel to be certain that kerosene or No.
1 home heating fuel is being used. Next, check the air
adjustment on the burner.
To adjust: start machine and turn burner ON. Loosen
two locking screws found in the air shutter openings
(refer to illustration) and close air shutter until black
smoke appears from burner exhaust vent. Note air band
position. Next, slowly open the air shutter until white
smoke just starts to appear. Turn air shutter halfway
back to the black smoke position previously noted.
Tighten locking screws.
If the desired position cannot be obtained using only
the air shutter, lock the air shutter in as close a position
5/32"
7/16"
Periodically Check Wiring Connections. If Necessary
To Adjust Electrodes, Use Diagram.
Electrode Setting: Top View
Electrode Setting: Side View
1/16"
1/16"
