Water Heater Connections; Water Heater Installations - Universal M3-20A Operator's Manual

WATER HEATER CONNECTIONS
WATER HEATER INSTALLATIONS
This engine is equipped with connections for the plumbing of
engine coolant to heat an on-board water heater. The water
heater should be mounted in a convenient location either in a
high or low position in relation to the engine, so that the con-
necting hoses from the heater to the engine can run in a rea-
sonably direct line without any loops which might trap air.
Hoses should rise continuously from their low point at the
heater to the engine so that air will rise naturally from the
heater to the engine. If trapped air is able to rise to the heater,
then an air bleed petcock must be installed at the higher
fit-
ting on the heater for bleeding air while filling the system.
NOTE:
If any portion of the heating circuit rises above the
engines closed cooling system pressure cap, then a pressur-
ized (aluminum) remote expansion lank must be installed in
the circuit to become the "highest point. Tee the remote expan-
sion tank into the heater circuit, choosing the higher of the
Mo connections for the return. Tee
at
the heater, and plumb a
single line up
to
the tanks location and the other back to the
engine's return. Instal/the remote expansion lank in a con-
venient location so the fresh water coolant level can easily be
checked. The remote expansion lank will now serve as a
check and system fill point. The plastic coolant recovery lank
is not used when the remote expansion lank kit is installed,
since this tank serves the same function.
->::,.... / . ,
---y~
HEATER ABOVE THE ENGINE
REMOTE EXPANSION
'l:
TANK j\ 1°
. I
t
~,
WATER
HEATER
THERMOSTAT
HOUSING
25
The pressure cap on the engine's manifold should be
installed after the engine's cooling system is filled with
coolant. Finish filling the cooling system from the remote
tank after the system is filled and is free of air and exhibits
good coolant circulation. During engine operation, checking
the engine's coolant should be done at the remote tank and
not at the engine manifold cap. The hose connection from the
heater to the remote expansion tank should be routed and
supported so it rises continuously from the heater to the tank,
enabling any air in the system
to
rise
up
to the tank and
out
of the system.
NOTE:
Air bleed petcocks are located on the engine's heat
exchanger and on the thermostat housing. Open these pet-
cocks when filling the engine'sJresh water S}'Slel7l to allmA'
air in the coolant circuil
!O
escape. Close lighl(V after al! the
air is removed.
~
THERMOSTAT HOUSING
HEATER BELOW THE ENGINE
WATER
HEATER