Mnalep
Member
Furnace is currently working. It had stopped a few days ago- the main burners were not firing up. It's running again now, but, I am worried I am 'right on the edge' of it stopping again.
When the burners were not coming on, I was inspecting the circuit, and then noticed if I jumpered a wire from TH to TH-PG the burners came on. I thought this meant the gas valve was ok, and that I just had a voltage issue in the circuit. That is when I tried things like replacing the limit, then replacing the tsat, and then splicing the tstat wires to remove a singed area.
Currently I am measuring mv across screws from both TH to TH-PG and from PG to TH-PG. I think the TH to TH-PG is the main solenoid in the gas valve, because when I put a green jumper wire between those terminal screws that is when I can force the main burner on. (see picture 1 for my gas valve and the green jumper wire I used to ignite the main burners.
The mv reading I get at TH to TH-PG is 187mv when main burners are lit (closed circuit), and 633mv with burners off (closed circuit).
I just don't know if I am 'on the edge of failure' or in the clear. I've read that 190mv - 200mv is the minimum, but is that with burners OFF, or ON?
Do I compare my reading of 187mv - burners ON, against the 190mv to 280mv? (meaning I'm 'on the edge').
Or, do I compare my reading of 633mv - burners OFF against the 190mv to 280mv? (meaning I am worried for o good reason) (PS: the burners were OFF, due to limit temporarily cycling the burners OFF for a while, when I measured 633mv.)
PICTURE 1: THE GREEN WIRE JUMPED FROM TH TO TH-PG WILL FORCE THE MAIN BURNER ON:
PiCTURE 2: MY White Rodgers GAS VALVE WITHOUT THE GREEN JUMPER WIRE IN THE PICTURE:
PICTURE 3: PILOT FLAME ON THERMOPILE:
When the burners were not coming on, I was inspecting the circuit, and then noticed if I jumpered a wire from TH to TH-PG the burners came on. I thought this meant the gas valve was ok, and that I just had a voltage issue in the circuit. That is when I tried things like replacing the limit, then replacing the tsat, and then splicing the tstat wires to remove a singed area.
Currently I am measuring mv across screws from both TH to TH-PG and from PG to TH-PG. I think the TH to TH-PG is the main solenoid in the gas valve, because when I put a green jumper wire between those terminal screws that is when I can force the main burner on. (see picture 1 for my gas valve and the green jumper wire I used to ignite the main burners.
The mv reading I get at TH to TH-PG is 187mv when main burners are lit (closed circuit), and 633mv with burners off (closed circuit).
I just don't know if I am 'on the edge of failure' or in the clear. I've read that 190mv - 200mv is the minimum, but is that with burners OFF, or ON?
Do I compare my reading of 187mv - burners ON, against the 190mv to 280mv? (meaning I'm 'on the edge').
Or, do I compare my reading of 633mv - burners OFF against the 190mv to 280mv? (meaning I am worried for o good reason) (PS: the burners were OFF, due to limit temporarily cycling the burners OFF for a while, when I measured 633mv.)
PICTURE 1: THE GREEN WIRE JUMPED FROM TH TO TH-PG WILL FORCE THE MAIN BURNER ON:
PiCTURE 2: MY White Rodgers GAS VALVE WITHOUT THE GREEN JUMPER WIRE IN THE PICTURE:
PICTURE 3: PILOT FLAME ON THERMOPILE:
