Hot water tank

[Diesel75]

The propane switch works fine, but elect switch will not turn the heater, what's up. how to fix. Changed the 2amp fuse & still the same.

[Jammer]

Probably a burned out element from someone running it while the water heater was empty. Check with a meter, or just replace, they're cheap but it can be difficult to get the old one off.

[OTRA15]

Jammer is probably right IMO, if you are sure that you have proper 120 volts to the water heater, which you can check via the exterior access door. Make sure the circuit breaker is not thrown.