I'm confused. Is your engine fresh water cooled (has coolant) or raw / sea water cooled? If it is raw water cooled I don't know if it will get got enough to heat the water tank. Also, if your boat is in salt water i don't believe the water heater is designed for salt water.
If the engine is fresh water cooled then the water heater gets connected to the engine coolant, not the sea water / raw water pump. The connection should be:
engine block water OUTPUT to water heater input, water heater output to engine heat exchanger input, engine heat exchanger output to engine block input.
Originally Posted by vtsailguy
Wonder if someone can help me here....
I am connecting up a hot water heater. The current tubing from the diesel for the water exhaust is 3/4". I have a bunch of 1/2" tube lying around to run to the heater's exchanger.
Does it matter to the engine to step down to a smaller size tube, or is it important to keep to the 3/4" (i.e. have to by more tubing).