H31 Removing Water Heater connections

[Alexandrina]

Dear Captains,

1983 Hunter 31, Yanmar 2GMF

Water heater hoses are getting old and need to replace them. However, we hardly use hot water while underway so I was thinking of removing the heater from the engine connections and simply use the heater while docked with shore power.

Can I simply remove the heater hose connections from the engine and plug them with 3/8 plugs meanwhile? Will the engine's cooling be adversely affected by removing additional cooling that we may be getting thru the hoses and the heater? What are your opinions?

Thanks a bunch.
Alex...

 

[Johnb]

This brings up an interseting question. On my 3QM30F water heat was attained by cobbling in 3/4 inch hoses from the block outlet, to the water heater and back from the water heater to the heat exchanger. This meant that the original few inches of about 1.5 inch diameter hose was replace by about 8 feet of 3/4 inch hose. Secondly, the thermostat only saw the water temperature after it had come back from the water heater. After an over heating incident, (caused actually by a blockage in the raw water) I restored it to orginal by buying a new piece of block to exchanger hose and leaving the water heater disconnected.

I see no reason not to do that, it is after all what Yanmar intended, but would like to restore hot water from engine waste heat. If anyone knows of a better way I would be interested.

 

[Alan]

Yes you can eliminate the heater from the cooling system of your engine. This will only allow the engine to reach full operating temp sooner. It will not adversely affect anything.
I would suggest however that having the water heating system hooked up will minimize the amount of needed electric current needed to produce hot water. Hot water in the heater retains heat for a very long time. Hot water produced by the engine cooling system from a prior days use is still usable the next day. I would opt for replacing the hoses.

 

[Alexandrina]

Thanks very much. Hoses removed and connections plugged. Engine ran without a problem, and actually it felt as if it ran a bit cooler that previously.

Yes, I will still replace the hoses but at least for now I can take my time to run them properly and any issues won't held me "grounded".

Best,
Alex...