Fluid Circulation Pump
©Aqua-Hot®
250-D03 Diesel Series Service Manual
REV 220302
p. 64
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 12V DC power supply to the fuel
solenoid’s (-) electrical terminal.
3. Intermittently apply the (+) lead of the power supply to the
fuel solenoid’s (+) electrical terminal.
4. Listen for the fuel solenoid to click (open and close).
5. If the fuel solenoid does not click, it must be replaced.
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.
NOTE:
If the fuel solenoid is not working, troubleshoot the
diesel burner’s high-limit thermostats (2). If they are tripped,
they will not allow the fuel solenoid to operate.
Fuel Solenoid Replacement Procedure:
1. Disconnect the C-plug harness’ violet (+) and brown (-)
wires from the fuel solenoid.
2.
Using a 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 ½”.
Remove the fuel solenoid shaft from the nozzle manifold
using a 16mm wrench. Discard the shaft and valve kit,
as replacements are provided with the new fuel solenoid
assembly.
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 the 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’ (+) and brown (-) wires to the
fuel solenoid’s (+) and (-) electrical terminals.
5. Test for normal operation.
Retaining Clamp
Ignition Cable
Positive Terminal
Negative Terminal
Lock Nut
Retaining Clip
Photo Disc
Figure 105
Burner Components
Figure 106
Fuel Solenoid Valve Coil
Electrical Terminals
(+)
(-)
Fuel Solenoid
Valve Kit
Fuel Solenoid Valve Assembly
Fuel Solenoid
Shaft
Fuel Solenoid
Valve Coil
