WATER HEATER SERIES
OPERATOR’S MANUAL
9
97-6149 • 97-6162 • 97-6133 • Rev. 3/04
Fuel Control System:
The machine utilizes a fuel solenoid valve located on the
fuel pump to control the flow of fuel to the combustion
chamber. This solenoid, which is normally closed, is ac-
tivated 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 gives an
instantaneous burn or no burn situation, thereby elimi-
nating high and low water temperatures, and combustion
smoke normally associated with machines incorporat-
ing a spray gun. 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.
Fuel Pressure Adjustment:
To adjust fuel pressure, turn the adjusting screw with a
5/32" Allen Wrench (located on the fuel pump) clock-
wise to increase, counterclockwise to decrease. Do not
exceed 200 PSI.
FIELD REPAIR INSTRUCTIONS
HP Fuel Pump:
1. Remove the screws 10/32" Allen Head from the ma-
chine hood.
2. Remove louvered hood.
3. With a 9/16" wrench, loosen (DO NOT REMOVE) the
two 3/8" x 3/4" HH NC serrated flange bolts that se-
cure the front panel.
4. With a 2.5 mm hex head wrench (Allen Wrench),
loosen the three set screws that hold the fuel pump
in the blower motor housing located on Idromatic
Boiler Assembly.
5. Carefully remove the fuel pump (Item #53) from the
blower motor, leaving the flexible zinc fuel line con-
nected, carefully bend the fuel line and fuel pump
away from the blower motor.
6. Locate the fuel pump/fan motor coupling.
7. Inspect the coupling for damage. The inside diam-
eter of fuel pump coupling requires flat on one side
to engage fuel pump, and the outside diameter re-
quires two male notches to engage the blower mo-
tor.
8. Perform a check to see if the fuel pump is turning
freely. Use an open end 7mm wrench or small ad-
justable wrench on fuel pump shaft.
9. Spin the fuel pump over in both directions using the
wrench for leverage. When the fuel pump is turning
freely (almost to the point you could turn it by hand)
it is ready to reinstall.
10. Align fuel pump coupler on pump shaft/fan motor.
Slide pump into fan motor. Secure pump with the three
set screws.
11. Test machine (make sure):
❑
Blower motor spins
❑
Fuel is on
❑
Machine has power to it
❑
Switch is on
❑
Flow of water through machine
❑
Thermostat is turned up
❑
Flow switch is adjusted properly
12. When HP is operating properly, turn machine off,
tighten front panel, and install hood and 13 self tap-
ping screws with recess washers.
