24
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.
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 No. 1 or No. 2 Heating Oil (ASTM D306) only.
NEVER
use gasoline in your burner tank. Gasoline is
more combustible than fuel oil and a serious explosion
could result.
NEVER
use crankcase or waste oil in your
burner. Fuel unit malfunction could result from contami-
nation.
Fuel Control System
These machines utilize a fuel solenoid valve located on
the fuel pump to control the flow of fuel to the combus-
tion chamber. This solenoid valve, which is normally
closed, is activated by a flow switch when water is
flowing through it. When an operator releases the
trigger on the spray gun, the flow of water through the
flow switch stops, turning off the 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 allows for an instantaneous
burn or no burn situation, thereby eliminating high and
low water temperatures, and combustion smoke
normally associated with machines incorporating a
spray gun.
CAUTION: Periodic inspection is recommended to
insure that the fuel solenoid valve functions
properly. This can be done by operating the
machine and checking to see that when the trigger
on the spray gun is in the off position, the burner is
not firing.
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.
Initial Air Adjustments
Allow sufficient air to obtain a clean burning flame by
loosening the lock screws and moving the air shutter
and if necessary the bulk air band.
Reduce the air supply until the flame tips appear
slightly smoky then increase the air just enough to
cause the flame tips to appear absolutely clean.
Oil Burner
Burner Air Adjustment
: The oil burner on this
machine is preset for operation at altitudes below 500
feet. If operated at higher altitudes, it may be necessary
to adjust the air band for a #1 or #2 smoke spot on the
Bacharach scale.
To adjust, start machine and turn burner ON. Loosen
two locking screws found on the air band and close air
band until black smoke appears from burner exhaust
vent. Note air band position. Next, slowly open the air
band until white smoke just starts to appear. Turn air
band halfway back to the previously noted position.
Tighten locking screws.
For higher altitudes, the air band opening may need to
be increased; for lower altitude, the .air band may need
to be decreased.
For higher humidity, the air band opening may need to
be increased; for lower relative humidity, the .air band
may need to be decreased.
For higher ambient temperatures the air band opening
may need to be increased; for lower ambient tempera-
tures, the air band opening may need to be decreased.
Adjust to your operating location's environment as-
needed for best smoke spot and performance
compliant with local, state, and federal regulations.
Karcher HDS 3.5/40 GE MT Operator’s Manual 9.807-942.0 - B
