Hello,
I'm new here, and I've been reading a lot (well, 4 or 5 pages anyway) of what's already been asked, and I haven't found my specific problem... yet.

This gas hot air furnace was installed circa 1987?
So,
Here's what's happening. (I actually timed these cycles with a second-hand.)
Turn up thermostat; furnace kicks in & burners start cranking.
Blower fan is triggered & runs for 44 seconds, then shuts off.
Burners continue operating for 1 minute, 41 seconds.
Blower fan is triggered & runs for 45 seconds, then shuts off.
Burners continue operating for 1 minute, 40 seconds.
Blower fan is triggered & runs for 45 seconds, then shuts off.
Burners continue operating for 1 minute, 38 seconds.
Blower fan is triggered & runs for 45 seconds, then shuts off.
Burners continue operating for 1 minute, 40 seconds.
Blower fan is triggered & runs for 45 seconds, then shuts off.
Burners continue operating for 1 minute, 49 seconds.

This process continues until the thermostat reaches the agreed-upon temperature. It is a Honeywell thermostat, probably rather vintage and I can see the model (?) numbers:
T87F2360 3 8443. It's currently on a setting of "4" in the little brass triangle.

Do you think this is a thermostat problem a fan switch problem or other? :confused:
If it's something I'll need a professional to look at, any guesstimates as to probable cost?

Any advice very much appreciated. I really hadn't budgeted on a furnace problem right now, you know? :(

Thanks so much,

Diane

Do you think this is a thermostat problem a fan switch problem

It could be either one.

Did this just start happening?

Have you lived there long enough to know if this is a new problem?

If it is a new problem it could be the fan switch on the furnace. Usually the thermostat will not change its anticipation settings since these settings have to be changed manually.

Have you changed the thermostat?

Hmmm... either one, eh?
But I got in the general ball park, though. I've impressed myself.

As I recall, (I own the house but hadn't lived here for a year & a half... silly me, I thought I'd get renovation work done if I lived somewhere else... HAH!), it had started to happen at the end of the last heating season when I was living here. And since I just turned the heat on for the first time today, it's all coming back.

I don't believe I've changed the thermostat, only to turn it down or up. Haven't fiddled with anything under the cover.

Thanks for taking the time to try to help figure this out.

Diane

Its your limited switch