I have another one for you.My port...

[Genny]

I have another one for you.

My port engine is supposed to heat the hot water tank while running. It's not working any more, and I'm sure it was last season. Any ideas. Did my mechanic forget to de-winterize something?

[wingless]

My understanding is that the hot water tank heat from engine coolant requires a supplemental circulation pump, to move water through that loop.

Does that pump exist and is it operational when the engine is running?

If that is the setup then IMO the pump should have a high temperature cutoff switch to limit the temperature rise of the hot water tank.

[Genny]

Where would that pump be located?

[wingless]

If a pump exists for that aftermarket modification, then it would be in the general area between the engines and the water heater.

The easy method for locating the pump is to follow the heater hoses from the engine to the water heater.

[Genny]

Ok, thanks. I'll check it out tomorrow.

[Genny]

Good morn,
Getting back to a previous issue, my water heater is heated by the port engine. Last time we talked about this you said that it was an "aftermarket" feature, with a circulater pump. I don't think so. All I can see is piping in and out of the tank, from the engine fresh/ antifreeze side of the cooling system, but it's not circulating. Could it be blocked?

[wingless]

The sales brochure for both of our boats lists: "Water Heater w/Exchanger".

On my 2000 380DA those heat exchanger hose barb fittings are unused, existing for an aftermarket modification.

Yes, it is theoretically possible that the water heater loop is obstructed. Careful disconnection of both ends at the engine would permit draining that loop, then running fresh water through that loop to confirm that it is not obstructed is possible.