On Wed, 19 Jan 2011 09:30:46 -0500, Bobo wrote:

On Wed, 19 Jan 2011 00:02:24 -0500, Bobo wrote:

On Tue, 18 Jan 2011 19:09:30 -0500, Bobo wrote:

I'm having a furnace problem. I turn the furnace on. The draft inducer
runs, the igniter lights up and then the gas goes on. It stays on just
about till the blower starts and then the gas goes off. The blower
keeps going for a little while then shuts off. I had an extra
thermostat and changed that out with no change. I cleaned the flame
sensor. The furnace has been running fine for years until this
happened today. Anybody know what's wrong?
Thanks

Thank you for your replies.
I cleaned the flame sensor again and checked continuity on the flame
rollout switches. I have continuity through the main limit switch but
still have not been able to check the auxitllary limit switch. I'll
have to take allot of stuff off to get to it and don't want to try
till I get a new flame sensor tommorow. The furnace was made by
Goodman Manufacturing Company and is a model GMP100-4. It's about
fifteen years old. It's the gas that goes off around the time the
blower starts. I've timed the burn time from 10 to maybe 20 seconds.
I can't find any way to reset the thing after it goes off. I turn up
waiting more than an hour before it will fire again. It does have an
LED code but it doesn't blink but stays steady which is the all OK
code. I'll try a new flame sensor tommorow and if that doesn't work

See, Vic, he stopped for the day to get a new flame sensor, when he
probably could have bypassed the one he has for a testing purposes.

I'll either call somebody or try to get to the aux limit. The board
has to come off to do that.


This morning I went down and turned the furnace on to see if my latest
cleaning and connector wiggling had helped anything. It did the same
thing and the gas shut off at about 12 seconds. I forgot to turn it
off again. About an hour later it came back on while I was upstairs. I
waited for it to go off but it didn't. Now it seems to be running
normally.

LOL. Ain't it always the way?

..Great an intermittent problem..this will be easy to fix.

Maybe it will never do it again.