I have an 8-year-old State brand (A.O. Smith) gas hot water heater with a Honeywell gas valve. The pilot light won’t stay lit. When I tried to re-light it the status light started to blink once every three seconds as it should. I could see the pilot flame through the window but I held the solenoid open in the pilot position for up to a minute to ensure that the thermopile was warm. Then I moved the gas valve dial to hot. I heard a click in the gas valve which I assume was related to opening the main gas flow. The pilot light went out and I did not see the main burner ignite. The status light stayed at one blink per 3 seconds for up to half a min but then went to 2 blinks in 3 seconds which is the signal for low thermopile voltage. I replaced the pilot assembly containing a new thermopile, along with the front cover plate, flex gas line, pilot gas line and all wiring (igniter, temperature and thermopile). This did not help.
What might be wrong? Does it make sense to replace the gas valve?
What might be wrong? Does it make sense to replace the gas valve?