Probably not a significant concern. As long as expansion tank is properly
located. Almost all automotive heaters have some or all of their plumbing
higher than the radiator.


"Jim Conlin" wrote in message
...
As long as the cooling system's header/expansion tank is even higher than
the highest point of the water heater loop, would adding a valve or two
for
burping the heater loop do the trick? You might even get by with plugs on
tees.


"Glenn Ashmore" wrote in message
news:1Gzyf.8431$Dh.3554@dukeread04...
OK. The Yanmar 4JH4 is on the stringers, exhaust run to the waterlock
and
raw water hose is on the strainer. Now I turned my attention to running
hoses to the water heater at the back of the engine compartment. The
instructions suggest that to avoid air traps the hoses to the heater
should
be run below the level of the engine heat exchanger. BUT the inlet and
outlet for the water heater feed is on top of the pump which is at the
top
front of the engine!

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
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