I have a State Select gas water heater Model PR 650 NRRTL, 50 gallons unit. The thermocoupler where it suppose to start the unit for heating does not work. The pilot light works but the unit will never start. Do you have any suggestion? Thanks.

The thermocoupler is bad or could be the gas valve on front of heater, That should take of your problem try the thermocoupler first cheaper then valve.

Does anyone know which configuration the valves haft to be in, in order to switch from heat to air conditioning? Any advice or help is greatly appreciated.