Aqua-Hot Hydronic Heating System Shop Manual 09/04
®
SECTION 8: DIESEL-BURNER SERVICE, MAINTENANCE, AND REPAIR INFORMATION
Fuel Pump,
continued
Fuel Pressure Function Test:
NOTES:
A:
A
Fuel Pressure Gauge
(reference Section 11 for special tools
information) is used to properly check the Fuel Pump’s pressure
setting; reference Figure 21. The
Fuel Pump
is preset to 145 psi
(the pressure required for proper fuel atomization at the
Fuel
Nozzle
). Perform the following procedures to check for a proper
fuel pressure setting.
B:
Be sure to use care when handling the
Fuel Nozzle
. Oils and/or
small dust or dirt particles from your hands may plug the nozzle’s
small orifice; reference Figure 9. A partially plugged orifice will
restrict fuel flow, which will affect the combustion process of the
Diesel-Burner
(i.e., excessive smoking from the exhaust pipe).
1.
Remove the
Fuel Nozzle
(reference Figure 17) and replace it with the
Fuel Pressure Gauge
; reference Figure 21.
WARNING:
A spark will appear across the
Ignition Electrodes
(reference Figure
16) for a brief moment after the
Diesel-Burner
has been activated.
DO NOT
attempt to make any fuel pressure adjustments until the
spark has disappeared. Failure to do so may result in serious
bodily injury (
i.e., an electrical shock
).
2.
Turn the
“Diesel”
switch
ON
; reference Figure 4. A pressure will register
on the
Fuel Pressure Gauge
once the
Fuel Solenoid
opens (after
approximately 10-25 seconds).
3.
If the
Fuel Pressure Gauge
registers a 145 psi pressure reading, no
pressure adjustment is necessary. Turn the
“Diesel”
switch
OFF
and
wait until the motor stops running. Remove the
Fuel Pressure Gauge
and reinstall the
Fuel Nozzle
(reference Section 8.6 for the Fuel
Nozzle’s “Replacement Procedure”). Reattach the
Diesel-Burner
Head.
NOTE:
If the
Fuel Pressure Gauge
registers below or above 145 psi, perform
the adjustment procedures listed below.
Fuel Pressure Adjustment Procedure:
1.
Turn the
“Diesel”
switch
ON
and wait until a pressure reading registers
on the
Fuel Pressure Gauge
(after approximately 10-25 seconds).
Then, adjust the fuel pressure by simply turning the
Pressure Regulator
Adjustment Screw
clockwise to increase fuel pressure or counterclock-
wise to decrease fuel pressure; reference Figure 21.
NOTE:
If the fuel pressure will not maintain a 145 psi setting, the
Fuel Pump
must be replaced; reference the Fuel Pump’s “Replacement Procedure”
in this section. Also, reference Section 10 for spare parts information.
2.
Once the pressure adjustment has been made, turn the
“Diesel”
switch
OFF
and wait until the motor stops running. Remove the
Fuel Pressure
Gauge
and reinstall the
Fuel Nozzle
(reference Section 8.6 for the Fuel
Nozzle’s “Replacement Procedure”). Reattach the
Diesel-Burner Head
.
!
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