Service manual

— Page 79 —
© January 2013 Aqua-Hot
®
600-D01 Series Hydronic Heating System Service Manual - Rev. A
SECTION 9: DIESEL-BURNER COMPONENTS
Fuel Pump:
The fuel pump draws diesel fuel from the vehicle’s
fuel tank and creates a preset pressure of 145 PSI,
which is required for proper fuel atomization. Ref-
erence the illustration below for a basic overview
and understanding of how the fuel pump functions.
Fuel Pump Testing Procedure:
1.
Clamp off and remove the fuel return and fuel sup-
ply lines coming into the Aqua-Hot unit.
2.
Attach a short piece of fuel line to both the inlet and
outlet fuel ports
3.
Submerse the opposite end of the temporary fuel
supply line in a container of diesel fuel.
4.
Place the opposite end of the temporary fuel return
line in an empty container.
5.
Turn the diesel switch
ON
to activate the diesel-
burner, and wait ten seconds.
6.
If fuel does not flow out of the return line into the
empty container, the fuel pump must be replaced.
7
. If fuel does flow through the fuel pump when ran
off an external source inspect the following in the
motor home:
A.
Check the motor home fuel tank for fuel. If the
fuel level is below 1/4 the Aqua-Hot diesel
burner will not operate.
B.
Inspect the supply fuel line for kinks which
would prohibit fuel flow.
C.
Inspect the supply fuel line for cuts, which
would cause the diesel burner to suck air.
D.
Inspect the fuel filter, to make sure all fittings
are tight, including hose clamps. Also, make
sure the fuel filter is tight.
E.
Inspect the Aqua-Hot for loose or cracked
fit tings.
F.
Inspect the supply fuel system for loose hose
clamps throughout
G.
Inspect the fuel pick-up tube in the tank., for
loose connection and pin holes in the pick-up
tube
Fuel Pump Cleaning and Maintenance:
1.
Check all fuel connections for tightness.
2.
Check the screen filter located in the fuel supply
inlet of the fuel pump for dirt particles. Clean and/
or replace if necessary.
3.
To adjust the fuel pressure refer to Appendix B:
Fuel pressure check and adjustment..
Do not remove the diesel burner at this time. Failure to
do so may result in serious bodily injury.
NOTE:
Prior to replacing the fuel pump, be sure to in-
spect the screen filter in the supply inlet of the fuel pump for
dirt particles. Clean and/or replace if necessary. A plugged
screen filter will restrict fuel from entering the fuel pump.
Also, be sure to inspect for cracked or loose fittings on the
supply line. A cracked or loose fitting on the supply line
will allow air to enter into the fuel system.
Figure 55