Oil Furnace keeps shutting down after providing heat for a couple minutes. What's going on?

[mshan]

Oil Furnace shuts down after couple minutes repeatedly. What's going on?
We have a 3 year old Lennox Furnace and returned home to find the house very, very cold.

We turned the furnace main switch off then on, reset house circuit breakers, and pattern keeps repeating.

Furnace starts and can feel some hot air out of vents, stays on about two minutes, then shuts down. A while later, it may kick in again and repeat same 2 minute on cycle.

What's going on?

 

[compuwiz1]

Bad thermostat? That's normally where to order to run or stop comes from, based on the ambient room temp.

 

[Pepsi90919]

Your furnace may have a computer and thus a diagnostic LED. Our Coleman furnace would try to ignite, run into a software glitch, and just blow cold air and the trouble LED indefinitely.

 

[mshan]

Is it possible that fan that's supposed to circulate air has broken down, and furnace is overheating and shutting down for safety purposes?

I can feel hot air, but flow is weak, and it seems to be mainly out of one vent located very close to furnace itself?

 

[IronWing]

thermostat
Improper venting (CO detector)
Blocked vents (back pressure)
Clogged filter

 

[mshan]

If any of the above, should service be able to fix quickly?

And how much should service tech charge?

 

[herm0016]

a buddy of mine is having the same problem. his runs for about 30 sec. and then shuts down for a few min, then runs for 30 sec. again. its kinda odd and annoying.

 

[Evadman]

thermocouple, thermostat, filter.

 

[mshan]

Hot air seems to be mainly coming out of one vent located almost above furnace.

Bedrooms further away are ice cold and can't even feel any air movement.

Air Filter? or some other filter?

 

[IronWing]

Do you have a combined heating/cooling system? Is there a louver (cookie sheet looking thing) that you have to move to switch from cooling to heating?

 

[Evadman]

Originally posted by: mshan
Air Filter? or some other filter?

For 50 cents, you should have just guessed Air filter.

 

[Ballatician]

im not sure but can you check out the thermocouple?

 

[mshan]

Separate Lennox furnace and air conditioner.

Have no idea what the thermocouple is, what it looks like, or even where it is.

 

[IronWing]

Originally posted by: mshan
Separate Lennox furnace and air conditioner.

Does the furnace use the same ductwork as the A/C? In other words, does the warm air enter each room in your house through the same vents that the cold air does?

 

[bctbct]

AT properly diagnosised my furnace problem last year. It would start the burner would kick on and then shut off. I have a gas unit though.

Flame detector, used some sand paper on it and it has worked fine since.

 

[mshan]

HVAC tech is here and said some sort of control panel is defective and needs to be replaced. I think it's in the thermostat section within the furnace itself, not the control panel upstairs.