Airxcel Aqua-Hot 600 Series, Installation Manual

Page: 21 / 63

Plumbing the Heating Loop
©Aqua-Hot® 600D Installation Manual p. 20
Engine Preheat
Engine Preheat & Motor-aide System
The Aqua-Hot 600D includes a motor-aide feature that
uses the circulation of the motor home’s engine to transport
the antifreeze and water heating solution from the Aqua-Hot’s
boiler tank to the motor home’s warm engine and back to the
boiler tank. The 600D also includes an engine preheat feature
that provides an easy engine start-up whenever colder weather
conditions are present.
Engine Preheat Location
• The inlet and outlet ports on the vehicle’s engine should
be kept as far apart as possible. This will ensure that the
entire engine is thoroughly preheated. See Figure 41.
• The engine’s coolant should be allowed to fl ow as freely
as possible to maximize the Aqua-Hot’s engine preheating
system.
• The engine’s inlet port is where the heated coolant is
transported to the engine block from the Aqua-Hot. This
port should be a high connection point on the engine block.
Refer to Figure 41.
• The engine’s outlet port is where the engine’s coolant is
transported to the Aqua-Hot. This port should be a low
connection point on the engine block or a pressure outlet
port on the engine’s water pump (Figure 41).
• Ensure that the engine preheat inlet and outlet hoses are
not placed too close to the engine’s turbocharger.
Plumbing Requirements
• Use ¾” ID (Inside Diameter) plumbing lines, automotive-
type heater hose for the engine preheating system.
• Lay both engine preheat lines as fl at as possible and
avoid any extreme rises in height in order to eliminate the
potential for air traps.
• Run both plumbing lines in areas where they cannot be
pinched off or damaged during normal operating conditions.
• Use one-piece engine plumbing fi ttings in order to reduce
the potential for coolant leaks. It is recommended that pipe
thread sealant be used on all engine plumbing.
NOTE: If assistance is needed in determining the best inlet
and outlet ports for a specifi c engine, please contact the
particular engine’s manufacturer or chassis supplier.
NOTE: Rubber coated, closed-type clamps are recommended
when securing the plumbing lines.
Plumbing Installation
1. Install both engine preheat plumbing lines and mark with
arrows and/or labels at both ends.
2. Drain the engine’s coolant.
3. Remove the selected inlet and outlet port “plugs” from the
engine.
4. Install and tighten the plumbing fi ttings into the inlet and
outlet ports on the vehicle’s engine.
5. Install and clamp both the inlet and outlet engine plumbing
lines, automotive-type heater hoses to the engine’s
plumbing fi ttings. Reference Figure 41.
6. Install and tighten a plumbing fi tting into the “inlet” port on
the Aqua-Hot’s engine preheating system. See Figure 42.
7. Attach and clamp the engine’s incoming plumbing line to
the Aqua-Hot’s outlet connection.
8. Attach and clamp the engine’s outgoing plumbing line to
the Aqua-Hot’s inlet connection.
9. Verify all fi ttings and connections have been tightened,
then refi ll the engine’s coolant system.
NOTE: The labels should indicate whether the plumbing
line is transporting coolant to the Aqua-Hot, or if it will
be transporting heated coolant to the vehicle’s engine.
Reference Figure 41.
NOTE: Should one or both of the selected engine ports
already have plumbing fi ttings attached, it may be necessary
to “tee” into those existing plumbing fi ttings. Please contact
Aqua-Hot Heating Systems at 574-AIR-XCEL (574-247-9235)
for additional assistance.