pop the cover off the thermostsat and check the ht antcipator setting. set it to .6 and try it again. if this is set wrong it generates heat and fools the stat into thinking the room temp is satisfied.
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Scootz
Did the blower come on at any point?
My guess is the "stack cutoff" sensor is bad. The idea is that shortly after the ignition goes on, the gas should lite and heat up the stack. If it doesn't, the ignition will be killed. But after several tries, it gets warm enough to stay on. Maybe the cold outside temp has something to do with it.
The sensor probably needs to be replaced. It's a safety-related item and the repair should be done by a licensed professional.
And if it does???? and if it does'nt???? Why not give some information/corrective action or a fix that goes with each answer--You're leaving the guy high and dry with no where to go with those type of comments. MLD
OK, I tried moving it from 5 to 6 (Heat anticipator) and the burner kicked in 4 times during the cycle. Well, I came back upstairs and turned the stat down, didn't want to see if it would kick in again.
Stone
Hi, I've got a forced air propane furnace, Luxaire model GSU082MF Series NAGOE (could be a Q) serial #1310002 Controlled by a Honeywell T87F heat only thermostat. This morning I was down in the basement and noticed that it had the initial ignition then that cut off after a while (normal burn) then a couple of minutes later a second ignition which ran a couple of minutes, when that cut off I headed up the stairs only to hear it kick in a third time for a couple of minutes. Total time for this was about 10 to 13 minutes. Before I went down there I had moved the thermostat only to the point which it kicked in, 60º F from 58º F so, it wasn't that drastic a jump. Yeah, I like it on the cool side. The outside temp was 19º F. I do not remember it ever acting in this manner and suspect there might be a problem, Yes? No? Thanks for any input.
Stone
I'm no expert, but here's my $0.02. Seems like your thermostat has lost the normal hysteresis that prevents this problem. There's a slide-wire heater in the thermostat called an anticipator. Try moving the slide slightly to clean up a poor contact.
Another possibility: did you relocate the 'stat or rearrange furniture such that it is now in a strong airstream from a register?
If all else fails, buy another furnace or move.
Roby
You said you moved the anticipator from 5 to 6 and gas cycling increased, did it run complete cylces-fan turning off. You indicated the fan was running, well, why not try moving it to 2. You probably need a pro anyway but it is worth a try
Ok, I looked at that slider (Heat Anticipator) in the stat and it is set at
5 should I set it higer or lower? Scootz suggested 6.Stone
Hi Scootz, hope you are having a nice day
On 11-Mar-05 At About 22:59:49, Scootz wrote to All Subject: Re: Furnace cycling
S> From: Scootz
S> pop the cover off the thermostsat and check the ht S> antcipator setting. it> set it to .6 and try it again. if this is set wrong it S> generates heat and fools the stat into thinking the room temp is S> satisfied.
If he didn't adjust it previously all this will do is make matters worse.
-=> HvacTech2
Hi Gary, hope you are having a nice day
On 12-Mar-05 At About 00:00:44, Gary Stone wrote to Gary Stone Subject: Re: Furnace cycling
GS> From: "Gary Stone"
GS> Ok, I looked at that slider (Heat Anticipator) in the stat and it is GS> set at 5 should I set it higer or lower? Scootz suggested 6.
Don't move it. it is set at a particular point for good control of the temp swing.
-=> HvacTech2
That would be 4 burns in one cycle, first burn then fan on then burner shuts down and comes back on two to three more times while the fan is running. Whole cycle about 10 to 13 minutes. I could try lowering it as you say. I have put a call in to the local HVAC guy here. Waiting for him to call back. He might be gone for the weekend though.
Stone
Hi, I agree with William and HvacTech2
I had the same kind of problem this fall, and I can tell you that the source of the problem might not be obvious at all for a non professional.
In my case, the problem was at the furnace level. The gas valve was defective and letting too much gas being burned, which made the furnace overheat, and thus the limit switch (I am not sure it is the correct name, it is the dial with 3 tabs) was shutting down the gas burning when the temperature was too high, then the temperature would lower and the switch would let the gas burning resume, and on and on...
Here is a forum with people that are friendly and willing to help you pinpoint the source of your problem, if that is really what you want. I had started a thread (which has diasppeared since then) on my problem back then and I got lots of good info. I called for a tech anyway because I dont like playing in those things, but I do like to understand how things work on the other hand. When I called the techs, I knew that I had an overheating problem.
To OP: heed the above, I have to ask "Is your filter clean and free of obstructions?"
I know that is obvious but I see it a half dozen times a year...
Joseph
Hi Gary, hope you are having a nice day
On 12-Mar-05 At About 01:27:53, Gary Stone wrote to Gary Stone Subject: Re: Furnace cycling
GS> From: "Gary Stone"
GS>> From: "Gary Stone"
GS>> Hi, I've got a forced air propane furnace, Luxaire model GSU082MF GS>> Series NAGOE (could be a Q) serial #1310002 Controlled by a Honeywell GS>> T87F heat only thermostat. This morning I was down in the basement GS>> and noticed that it had the initial ignition then that cut off after GS>> a while (normal burn) then a couple of minutes later a second GS>> ignition which ran a couple of minutes, when that cut off I headed GS>> up the stairs only to hear it kick in a third time for a couple GS>> of minutes. Total time for this was about 10 to 13 minutes. Before GS>> I went down there I had moved the thermostat only to the point which GS>> it kicked in, 60º F from 58º F so, it wasn't that drastic a jump. GS>> Yeah, I like it on the cool side. The outside temp was 19º F. I do GS>> not remember it ever acting in this manner and suspect there might GS>> be a problem, Yes? No? Thanks for any input.
GS>> Stone
I can't check it for sure since I am not there but it sounds like the unit needs to be checked and cleaned. the thermostat is probably fine.
-=> HvacTech2
I did call the local HVAC guy here in town but had to leave a message. Hasn't called back, could be out of town. In the mean time I've got the wood burning stove going. Nice to have that to fall back on. Funny how these things always seem to happen on a Friday or Saturday. Thanks for the help.
Stone
You know, I did just replaced the filter with one of those pleated ones in lieu of the cheap fiberglass one that was in there about a week ago.
Stone
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