Fluid Circulation Pump
©Aqua-Hot®
250-D03 Diesel Series Service Manual
REV 220302
p. 66
8. Reconnect the C-plug harness’ violet (+) and brown (-)
wires to the fuel solenoid’s (+) and (-) electrical terminals.
9. Insert both the ignition cables into the rubber grommet and
slide into the appropriate notch on the blower casing.
10. Reconnect the ignition cables to the ignition electrodes.
11. Reinstall the photo disc and secure it in place with the
retaining clip.
12.
Reconnect the flame sensor’s green wire to the green
C-plug harness and the blue wire to the C-plug harness’
violet wire. Install rubber grommets around the harness
wires, and set into place.
13. Follow the directions for reattaching the diesel burner on
Page 50.
14. Test for normal operation.
NOTE:
Do not adjust the fuel pressure regulator of the new
fuel pump, as it has been factory preset.
NOTE:
Failure to use the new gasket rings or the correct
order placement could result in a fuel leak.
Inspect the nylon drive gear’s cavity inside the cast-
aluminum blower casing for fuel stains� If fuel stains are
present, a replacement of the bearings and/or the entire
blower casing may be necessary� Leaking fuel could cause
bearing seizure, resulting in potential damage to the
internal bore/bearing of the blower casing
NOTE:
Check the ignition electrodes for proper adjustment
prior to reattaching the diesel burner.
Fuel Supply Banjo Tube
Fuel Return Banjo Tube
Fuel Solenoid
Fuel Pump
Photo Disc
Figure 108
Burner Components
nozzle stand and the ignition electrodes.
3. Loosen the supply and return banjo bolts to remove the fuel
supply and return pipes from the fuel pump. Disconnect the
high pressure fuel pipe from both the fuel pump and the
nozzle stand. Discard the high pressure fuel pipe, gasket
rings, and banjo bolts, as replacements are provided in the
new fuel pump kit.
4. Remove the four nozzle stand plate screws that secure the
nozzle stand plate in place. Remove the nozzle stand plate
by pulling on the nozzle stand until the plate releases from
the cast-aluminum blower casing.
5. Remove the two pump mounting screws that secure the
fuel pump in place. Turn the nozzle stand plate over and
remove the snap ring from the fuel pump shaft, using snap
ring pliers. Remove the nylon drive gear and then the fuel
pump.
6. Attach the new fuel pump to the nozzle stand plate with
the two pump mounting screws. Turn the nozzle stand plate
over to install the nylon drive gear on the fuel pump’s shaft
and secure in place with the snap ring. Dab the teeth of the
nylon drive gear with white lithium grease (IsoFlex LDS-18
is recommended).
7. Fit the nozzle stand plate inside the cast-aluminum blower
casing and secure in place with the four nozzle stand plate
screws. Install the grommets on the fuel return and supply
banjo pipes and secure the pipes to the fuel pump with the
new banjo bolts and gasket rings.
