Capping Hot Water Heater to Engine

[Jackz]

I have discovered a slow leak from hot water heater to engine, which causes pressure to build up and spew antifreeze all over engine room. I had someone suggest that I simply cap the water coming in and out of the water heater to the engine, and same thing on the engine. Fresh water/antifreeze in the closed system will still circulate, as will raw water cooling. My question is if the pump that circulates the hot water heater to the engine (if there is one?) will have an issue without any water circulating. I can still heat water using 110 or running generator, just won't have engine heating. I'm foggy on how this all works, Yanmar 3JH5E.

[a64pilot]

The pump is your engine fresh water pump.
The water heater is identical in function to the heater in an automobile, and many auto’s regulate heat by restricting water flow with a valve, so blocking the water flow isn’t going to hurt.
I’d still disconnect both lines though and simply connect a short loop of hose myself as opposed blocking flow.
You could also install good valves in the hoses and block flow.

Also be aware that it’s possible that your fresh water supply is now contaminated with poisonous anti freeze, I’d drain and flush the water tank myself.