Additional circuit in diesel cooling system ?

[Lepke]

I have a heating system loosely related. I have a oil fired boiler that is expensive to run. I also have a pellet stove and diesel stove, both with coils to heat. With those and the engines I have various ways to heat the boiler and water heater.
My contribution is insulation is important. However you gather warmth, without good insulation on the plumbing, you loose most of the heat you are moving somewhere. Even insulate the pump if possible. Put a temperature gauge where you leave the coil and where it enters the water heater and you will see.

[tinkrman69]

Ondemand hot water heater running off the engine cooling system? Now a water heater running off an engine cooling system Ive heard of...I'm not all knowing tho.

But the plumbing mod you state wouldn't be very efficient. you'd do better running the fresh water off the supply side of the heater through the on deck coils and back to the hot water heater. adding the pump and circulating it through the heater. You would have the heaters water volume and the volume of water in the coils on deck, increasing the amount of hot water and the insulation of the water heater would keep it hot longer into the night if you turned off the circ. pump after sunset. Why try to transfer the heat twice?

You would also be eliminating the chance of getting an air block in the engine cooling system, switching the valves back and forth, and over heating the engine at an inopportune time.