Has anyone made a water heater?

[kenking]

Thinking I could make a water heater using the engine heat. Sort of a tank with a coil of copper tube in side that the hot engine coolant runs through. I'm thinking I could use a pressure relief valve from a house water heater to get from making myself a bomb. Any thoughts or experience with this?

[Cornbread Red]

Essentally a heat exchanger then. Myself, I'd stick to a comercially made one. I think it'd cost more to fab one from scratch than to just buy something like the little propane ones you see in camping stores and Walmart.

Chip

[Davydd]

We generally only use hot water after supper or in the late evening before going to bed or the first thing in the morning. In all instances the engine is cold. Rarely or never would we need hot water anytime soon after running the engine.

[K-mann]

Interesting idea, but sounds like more trouble than its worth. Unless you could find a way to insulate a container that would hold the water once heated....

We opted not to install a hot water heater. We can heat water on the stove or use one of those solar showers.

[kenking]

Well, I've had two ideas on this, and not too sure I'm really going to try either one really. The first approach would be to run a coil of copper tubing inside an insulated tank and heat water as hot engine coolant passed though the coil.
The other approach could also use a tank, but the water would be heated by passing through a copper tubing coil wrapped around an exhaust pipe. I say "could use a tank" because this would also be a way to provide tankless hot water as long as the engine was running for the few minutes one needed water.