Airxcel Aqua-Hot 600 Series, Installation Manual

Page: 23 / 63

Plumbing the Heating Loop
©Aqua-Hot® 600D Installation Manual p. 22
Fuel System
Diesel Fuel System
The following section outlines the requirements for diesel
fuel delivery to the Aqua-Hot unit. Read and adhere to all of the
outlined requirements to ensure best, and safest performance
of the Aqua-Hot.
Fuel Filter Location
• Mount the fuel fi lter assembly in a location that provides
easy access for replacing the fi lter and for catching any
potential fuel spillage when servicing.
Fuel System Requirements
• The diesel fuel supply should be drawn directly from the
vehicle’s main fuel tank or from a separate auxiliary fuel
tank, if applicable.
• The fuel tank should be equipped with a dedicated fuel
pick-up pipe (outlet and inlet port). Reference Figure 43.
• Use ¼” ID (Inside Diameter) fuel lines.
• The combined length of the supply and return fuel lines
should not exceed 100 feet in total length. Reference
Figures 44 & 45.
• All fuel-fi tting hardware (at the vehicle’s fuel tank: fuel fi lter
and Aqua-Hot fuel parts) must be ¼” NPT or greater with
a ¼” barbed fi tting. Fuel fi ttings less than ¼” NPT may
restrict fuel fl ow, thereby compromising the diesel burner’s
performance.
NOTE: If an auxiliary fuel tank is required, be sure to
consult the ANSI/NFPA 1192 Handbook concerning heating
system’s diesel fuel system specifi cations.
Fuel System Installation
• Both fuel lines (supply and return) should be laid as
fl at as possible and any extreme rises in height should
be avoided in order to eliminate any potential air traps.
• Run both fuel lines in areas where they cannot be
pinched, kinked, or damaged during normal operation.
• Run the fuel tank outlet fuel line past the fuel fi lter
location in preparation for Step 7.
1. Run two ¼” fuel lines from the fuel tank inlet and outlet
ports to the Aqua-Hot.
2. Be sure to secure all fuel lines where necessary and apply
protective shielding in areas where chafi ng may occur.
3. Label both fuel lines indicating whether they are an
outgoing line or incoming line.
4. Connect the Aqua-Hot’s fuel lines to the vehicle’s fuel tank.
5. Install and tighten the appropriate fuel fi ttings onto the
Aqua-Hot’s fuel ports, as well as the two ports of the fuel
fi lter. Reference Figure 46 & 47.
6. Connect the inlet and outlet fuel lines to the Aqua-Hot’s fuel
port connections.
7. Cut the fuel line at the fuel fi lter mounting location and
connect the fuel lines as illustrated in Figure 46.
NOTE: Be sure the fl ow of fuel through the fi lter is in the
correct direction as shown in Figure 46.
Vehicle Fuel Tank
Outlet Port:
to Aqua-Hot’s
fuel fi lter
Fuel Pick-Up Pipe
NOTE: The fuel pick-up pipe should not extend further than
the motor home’s engine fuel supply pick-up and should be
consistent with the on-board generator’s fuel supply pick-up
length.
Figure 43
Inlet Port:
from Aqua-Hot’s
outlet port
A kinked fuel line (return side) will increase fuel pressure
to hazardous levels, and may cause a fuel line to rupture.
A kinked fuel line could also severely damage the diesel
burner’s internal fuel system.