coleman furnace?

Question

Furnace runs, shuts off and comes right back on. Replaced the thermostat & that didn't help. Gas bill is going to be bad this month. Any ideas? gary

Answer 1

we have had the same problem. i talked to coleman to see if it was one of the models that was recalled and it wasnt. they said several things could cause it. assuming it's a gas furnace, the upper limit switch could be switching it off because the firebox was getting too hot before it completeed it's heating cycle, once it cools it starts up again. the ducting could be insufficient to allow the hot air to move out at a rate that will allow enough heat flow resulting in the upper limit switch tripping.
the thermostat could be in a location that warms quickly then shuts off snf cools just as quick- they reccomend moving the thermostat. also if its on a exterior wall it is cooling down too fast. they also reccomend making sure the filters were clean and too not use the super efficient filters because they impede the inlet airflow.
our problem was when they installed the furnace, the installer dropped the furnace down and collapsed part of the ducting underneath restriciting airflow and causing a heat buildup. it's better now - somewhat, and i have a thermometer that lets me see if the room is getting to temperature before it shuts off.

if you have a digital thermostat, are the batteries good and the low end models dont seem to work very well

hope it helps

Answer 2

With forced air system this can often be just a clogged air filter. The thermostat calls for heat, the furnace kicks on. After the stack heats up the blower is turned on to distribute the heat. With a clogged air filter, not enough air passes over the heat exchanger and the stack goes overtemperature, shutting off the furnace (oil burner or gas flame) but the blower keeps going. After the stack cools a bit the furnace kicks on again.

If that describes what you are experiencing, change the air filter.

Most other problems trigger the system to stay off, requiring the rest button to be used before it would work again.

Answer 3

Probably caused by a "flash back" of gas which trips the processor and causes a shut down and SELF RESETS

Try doing this: On a Honeywell or any other gas regulator valve, there is an adjustment for gas pressure to the nozzles. There is a CAP to access that adjustment right on top side of gas valve. Remove that cap. Deep down you l see a screw to adjust. Turn that screw 1/2 turn COUNTER CLOCKWISE. That will LOWER the gas pressure to the nozzles and stop Flash Back signal activation and avoid the drop out of the furnace. Replace the cap and you are done. What happens over time is these springs in the gas pressure regulator weaken ever so slightly and cause an INCREASE in gas pressure to the nozzles an thus the flash back problem.

Answer 4

We had a new coleman high efficiency gas converted to propane. It blew ventor motors and electronic modules so regularly, and parts costs were so inflated compared to other companies that after four years-- and of course a crappy one year warranty-- we pulled it and put in a forced air electric. Heat is expensive, but at least now its consistent. I will never buy a coleman product again.