14
S E R V I C E
M A N U A L
L A S E R H E A T I N G S Y S T E M S
L A S E R H E A T I N G S Y S T E M S
Servicing
Section 3
STEP 2: Inspection and Cleaning
A. Pull the fuel strainer out of the fuel sump.
B. If the strainer is dirty (but undamaged), rinse the fuel
strainer in fresh, clean kerosene to remove all
particles. Replace the fuel strainer if necessary.
C. To drain the upper portion of the fuel sump, carefully
loosen
the drain screw
, there is no need to remove
(phillips head screw) which is located to the left of
strainer cover.
STEP 3: Reassembly
A. Push the new cleaned fuel strainer back into the
bottom of the fuel sump.
B. Replace both the strainer gasket and the strainer
cover if necessary.
NOTE:
Carefully align the screw holes in the gasket
and strainer cover.
C. Wipe up any spilled fuel.
NOTE:
Be sure to unscrew the drain screw to remove
all the remaining fuel from the fuel sump at the
end of each season.
3-9
Replacement of Fuses
A short circuit or similar electrical malfunction could
cause a fuse to blow. Troubleshoot the cause of the
blown fuse.
Replace the fuse as follows:
WARNING:
Do not replace fuses while power is
“ON”.
STEP 1: Removal of Fuse
A. Unplug the heater. Remove the front panel assembly.
B. Remove the fuse from fuse holder, located on the
main circuit board.
STEP 2: Installation of New Fuse
A. Install new fuses into the fuse holder. The fuses must
be a 125V, 10 amp type and a 125V, 3 amp type a
re
marked on the main circuit board. Do not use
oversized fuses.
B. Replace the front panel assembly and plug the heater
into the electrical outlet.
IMPORTANT:
Whenever the heater is unplugged,
t h e s e t - b a c k t i m e r m u s t b e
reprogrammed after the power is
restored.
3-10
Fuel Contamination
Fuel contamination is often difficult to diagnose, even
though it will adversely affect the heater operation and
performance. The best course of action to take when
fuel contamination is suspected
is
to examine all of
the system’s fuel filters, beginning with the fuel storage
tank. If a Laser kerosene lifter is part of the fueling
system, examine and clean the unit’s filter, as well as
the strainer located in the fuel sump.
When it has been determined that water or some other
contaminant has infiltrated the fuel, the following
procedure should be used:
WARNING:
Before proceeding further, unplug the
heater.
STEP 1: Remove Contamination
A. Close the fuel valve of the tank and the fusible link
valve on the heater.
B. Drain the contaminants from the external tank, or
disconnect the fuel supply hose and clean the
contamination from the removable fuel tank (Laser
560). Refill with fresh, clean fuel.
STEP 2: Clean the Heater
A. Clean the fuel inlet strainer inside of the fuel sump.
B. Remove the front panel assembly and the fuel pump on
the fuel sump. Clean the fuel pump filter.
C. Using clean paper towels, thoroughly wipe the bottom
of the burner, the burner ring, the flame rod sensor,
and the heat chamber.
Replace the burner mat, if necessary.
STEP 3: Reinstall Cleaned Components
A. Replace the components correctly and install a new
gasket, if necessary.
B. Open the fuel valve on the external tank, the
removable fuel tank, and the fusible valve, replace all
covers and supply power to the heater.
If the problem still exists and contaminated fuel is
suspected, it can be checked.The fuel filter or the water
block filter in the fuel line is always required to minimize
any fuel contamination.
Test run the heater to see if the problem clears up, using
new clean fuel.
