Help please. I'm stumped. Bradford White Defender gas water heater will not light. It has a Honeywell gas valve. I have cleaned the bottom filter and the burner, replaced the gas burner assembly, changed the piezo igniter, and replaced the inner doors (came with a new resettable thermal switch). The gas is turned on. I depress the pilot switch and can hear gas flowing. I strike the piezo igniter several times while keeping the pilot depressed but I never see a flame. The Honeywell gas valve starts blinking once every three seconds telling me that everything is fine. However, I cannot see the pilot light. I switch the knob to hot or A anyway and wait three to five minutes. No flame.

With the gas burner assembly out, I test the piezo igniter and can see the spark. Because the whole assembly was replaced, I am assuming the thermopile is fine. It's new. I have depressed the resettable switch each time I have reassembled the unit. Any suggestions? Thanks!

Many times the pilot is difficult to see. But the flame must be heating the sensor for it to light. Good luck.

@srloren. Assuming the pilot is lit and I cannot see it, shouldn't the burners kick on after waiting for 5 minutes? I assumed the pilot was lit (gas valve blinked once every three seconds). Then waited for five minutes after adjusting the thermostat. No flame heard or seen. Any other suggestions? Thanks.

After the pilot lit, did you turn the temp knob up to "A" from the "pilot" setting? It sounds like the pilot lit for it to blink "ok".

Thanks Bruce. I cannot verify that the pilot actually lit. I could not see a pilot flame. After the gas valve started blinking the last time, I kept the knob held in a little longer and then switched to the "A" setting. Waited 5 minutes and never saw a flame. Nor did I ever hear a whoosh that would give me an indication of a flame even if I could not see one. The gas valve blinks normally every time but there is never a verifiable pilot and there is no verifiable flame. Still stumped on this one unless the gas valve is faulty.

Still no resolution. Any other veterans out there who can offer a suggestion for this water heater that thinks the pilot is lit when in fact it is not? Thanks.