Service manual
— Page 78 —
© January 2013 Aqua-Hot
®
600-D01 Series Hydronic Heating System Service Manual - Rev. A
SECTION 9: DIESEL-BURNER COMPONENTS
Fuel Solenoid:
The fuel solenoid allows the flow of diesel fuel to
the diesel-burner’s fuel nozzle.
Fuel Solenoid Component Test:
1.
Locate and detach the C-plug harness’ violet (+)
and Brown (-) wires from the fuel solenoid.
2.
Connect the (-) lead of a 12 volt DC power supply
to the fuel solenoid’s (-) electrical terminal.
3.
Intermittently apply the (+) lead of the power sup-
ply to the fuel solenoid’s (+) electrical terminal.
4.
Listen for the fuel solenoid to click (i.e. open and
close).
5. If the fuel solenoid does not click, it must be re-
placed.
Fuel Solenoid Replacement Procedure:
1.
Disconnect the C-plug harness’ violet (+) and
brown (-) wires from the fuel solenoid.
2. Using an 8mm wrench, remove the lock nut and flat
washer from the end of the fuel solenoid shaft and
then pull the fuel solenoid away from the nozzle
stand approximately 1/2”. Remove the fuel sole-
noid shaft from the nozzle manifold using a 16mm
wrench. Discard the shaft and valve kit, as replace-
ments are provided with the new fuel solenoid as-
sembly.
3.
Insert the contents of the new fuel solenoid valve kit
into the new fuel solenoid shaft. Slide the new fuel
solenoid onto the fuel solenoid shaft. Thread the
new fuel solenoid shaft with fuel solenoid to the
fuel nozzle manifold and tighten. Secure the fuel
solenoid in place with the new flat washer and lock
nut.
4. Connect the C-plug harness’ violet (+) and brown
(-) wires to the fuel solenoid’s (+) and (-) electrical
terminals.
NOTE:
In order to perform the following procedures it is
necessary to detach and reattach the diesel-burner head. Be
sure to review the detaching/attaching instructions.
NOTE: If the fuel solenoid is not working troubleshoot the
diesel burner’s hi-limit thermostats. If they are tripped they
will not allow the fuel solenoid to operate.
NOTE:
If a long after-smoking condition exists during the
diesel-burner’s purge cycle, the fuel solenoid valve kit may
need to be replaced.
Figure 54