Hi Alan, a bit of a whimsical topic...
The water heater on our boat, as with most other Hunters, is operated with AC current, which means shore power or generator sourced. The heat exchanger on the engine will heat the water going into the water heater as long as it is running. If there is no shore power or engine running then no light will come on and no water will heat. Our water heater does not have a motor so I'm not sure what motor you reference.The AC section of our power panel has a circuit breaker for the water heater. I'm unaware of any other reset switch for it. Perhaps you could describe in more detail your issue.Terry