RE: 1997 Coachman Catalina Water Heater
The by pass valve is behind the water heater. You might need to open a drawer or open a cabinet or open an inside storage area to reach behind the water heater. You might need a new thermostat which can be replaced on the outside of the water heater. The thermostat looks like two metal buttons usually one on top of the other.
RE: Looking at class c questions on maintenance
Depends on the dealer. The ford dealer in my town will not do any kind of work on RV's including tires. Check with your local dealer.