Weird residue on gas pipes of water heater thermostat bottom

harry007

My honeywell thermostat is flashing 5 times indicating it's time replace thermo sensor. I look around and found weird crystal residue on the bottom of the thermostat, especially the metal parts for gas pipes.

After moving away the valve, there's also residue on the internal surface of the back cover.

I'm wondering if the residue is from water leak, gas leak, or just as expected from that whole?

HVACNUT

So the temperature sensor is attached to the gas valve? Can we see it?

I've never seen a gas valve for a water heater come apart like that. I've replaced a few, and the whole thing spins out. The sensor is in the water. With that one, it looks like a dry well, and the sensor inserts. It could be conductive fluid.

Larry Weingarten

Hi, I found this:

https://www.youtube.com/watch?v=NG1nObdxzn8

They seem quite focused on this type of Honeywell valve. They don't answer the present question, but the info might help still.

Yours, Larry

109A_5

" So the temperature sensor is attached to the gas valve? Can we see it?

I've never seen a gas valve for a water heater come apart like that. "

We kind of went through that in another thread, there is two thermistors in that well connected to the circuit board with a three conductor ribbon cable. The circuit board controls the gas valve. There other Youtube videos of the disassembly of the gas valve assembly.

I'd say the black plastic part was cracked and leaking and needs to be replaced. I believe the tank OEM and Honeywell recommend replacing the whole gas valve assembly.