Regency WH-U U41 - burner won't shut off

[krc]

Pilot light works fine. I can startup the main burner fine with the toggle switch, though I notice that it takes a couple seconds now where it used to be instantaneous. But, when trying to shut off it is slow to shut off with the toggle (the main burners) - and after it is hot the toggle switch can't EVER shut off the main burner. Have to shutoff the valve itself to turn it off, or the gas line valve itself.

Any ideas?

I would think this is a toggle switch failure, but the fact that it can turn on and then off when 'cold' leads me to think this could be something else.

Thanks!
Karl

 

[DAKSY]

I would look at replacing the switch first, but you can check it by using a jumper wire on the valve.
Jump the TH & TH-TP (or TP-TH) terminals. If the wire turns it on & off immediately, the switch is suspect.

 

[krc]

I would look at replacing the switch first, but you can check it by using a jumper wire on the valve.
Jump the TH & TH-TP (or TP-TH) terminals. If the wire turns it on & off immediately, the switch is suspect.

KRCH: Thanks. I took off the "black" lead in the the TH-TP post and then was able short between the TH & TH-TP and get the fireplace lit. When I took the short off the two posts then the fire went out. So - seems to indicate a faulty switch. So - I pulled off the SPST switch and shorted the two wires into the terminal. Fire started right up, but - very strangely - when I separate the wires the fire does NOT go out. I notice that the red lead goes into a "spill switch" and then into the rocker. It seems like this should always pass through current unless there is a high fire / co issue?

Really strange... Any other ideas?

 

[DAKSY]

Baffling...Maybe you should PM Heatsource (Dave Gault) or FSappo...
One of them might have another idea..

 

[fire245]

Baffling...Maybe you should PM Heatsource (Dave Gault) or FSappo...
One of them might have another idea..

just a theory but you could still be completing the circuit via the thermal pile. If the copper lead is touching ground you have a potential difference and a completed circuit back to the valve.

 

[krc]

Update: I took pics of the valve and the circuit where I removed the SPST switch. I also just basically moved some of the wires around and also vacuumed the dirt from the area as well as around the insert. Once I did that, it now seems to turn on and off as expected (when I connect or disconnect the black/white wires in the attached photo). Still don't know how this is really resolved, but I guess I will throw the switch back in and reassemble. Hate to do that without fully understanding the cause - intermittent issues are not easily solved for long term reliability.

FIRE245 - Doesn't a thermocouple convert heat to electrical energy? So - are you theorizing that the leads to the thermopile are shorting prior to the pile then the voltage will always be zero? I would have though the gas valve would have handled that as some sort of "error" because I think a thermopile always puts out a voltage signal whether there is flame or not. I suppose that it could be the voltage "drops" when the flame is on the pile, and hence perhaps a "zero" would make the valve think it should remain on? not sure.... but will take a look when this happens again and measure the drop.

How easy is it to get to the thermopile? Looks like I have to open the "window", remove the logs, etc?

Thanks for everyone's help with this thread. Much appreciation for your ideas....

 

[Heatsource]

How easy is it to get to the thermopile? Looks like I have to open the "window", remove the logs, etc?
]

not familiar w/your stove... some are easier to replace t-piles in than others...
\
your primary issue sounds like wiring, and probably a bad on/off switch

test by disconnecting the wires to the switch and touching them together, if it works perfectly every time, replace the switch...