Honeywell thermostat 5 flash error

[twilite]

Hi, I'm seeing a 5 flash error code on a Bradford White water heater with Honeywell thermostat.

I can reset it by turning the dial to off and unplugging the thermocouple wires, then plugging back in the wires, pressing down the dial for 3 seconds, and then setting the temperature. The water heats up hot, but after 1 cycle, the error code returns.

The water stays hot for about an entire day, but requires this manual reset to trigger heating the water each time.

I replaced the thermocouple with a new one, no change. When I measure the voltage from the thermocouple wires, I see 110mv from the pilot. The pilot stays lit just fine.

What could be the problem? Thank you so much for any help.

 

[GReynolds929]

Replace the temperature sensor not the thermopile. The temperature sensor is the round sensor on the front of the burner door with the red button on it and two wires connected to it.

 

[Sponsor]

 

[twilite]

Just to confirm, does this mean replacing the entire Honeywell thermostat box (model WV8840A1000)? This requires disconnecting the gas line and draining the tank?

The only other round object on the burner door with two wires connected is the thermocouple switch, which connects between the thermocouple and the Honeywell box. I tested this for continuity and it measured 0.04. I also tested with bypassing it so the two red wires just connected directly. The burner still fired up successfully, but after about 5 minutes, the Honeywell thermostat began the 5 flash error again.

Thank you for your help.

 

[Fitter30]

Needs new gas valve. Check with the heaters manufacture.

 

[Master Plumber Mark]

If your heater is still under 6 years old you just need to get a complete box of replacement parts from the supply house and change the whole assembly including the gas valve itself