Steve,
The refrigerator and water heater do not run through the inverter, so it sounds like you have a tripped main breaker, a hard wired Surge Guard, or a defective transfer switch that is blocking any 120 volt current. About the only way to determine what your problem is after checking the breakers is to take a volt meter and trace the 120 volt circuit, starting at the transfer switch. If you have power out of the transfer switch and there is no hard wired Surge, go to the main breaker box. The readings from these locations should determine what your problem is.
Gerald