Westerbeke 12C-TWO Operators Manual And Installation Manual page 53

Hoses should rise continuously from their low point at the heater to the engine so that trapped air will rise
natnrally 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 fitting on the heater for bleeding air while filling the system.
Avoid loops in hose runs which will trap air.
NOTE: If any portion of the heating circuit rises above the engine's own pressure cap, then a
pressurized (aluminum) remote expansion tank must be installed in the circuit to become the
highest point. The remote expansion tank's part number is 24177. Tee the remote expansion
tank into the heater circuit at the heater connection, choosing the higher of the two for the return.
Tee right at the heater and plumb a single line up to the tank's location and the other back to the
engine's flow control. (Refer to the illustration on the previous page.) Install the remote
expansion tank in a convenient location such as in a sail locker so the fresh water coolant
level can easily be checked. The remote expansion tank will now serve as a check and system
fill point. The plastic coolant recovery tank is not used when the remote expansion tank kit is
installed, since this tank serves the same function.
The pressure cap on the engine manifold should be installed once the engine's cooling system is filled
with coolant. Finish filling the cooling system from the remote tank once 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 as to
rise continuously from the heater to the tank, enabling any air in the system to rise.
Refer to the illustrations on the previous page.
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Westerbeke Engines