I have a Carrier central air and furnace(furnace model 58GS050-3), it was built around November, 1985. It has carrier air conditioner indoor cooling coils box model 28AC030-911 laid on top of the furnace. Everything was working until one week ago. Now with the thermostat off and the fan set to...

On my Carrier furnace (model 58G5100-2) the igniter starts the pilot, and most times the pilot starts the burners after a minute or two and then the blower motor starts. Other times, pilot lights the burners which burn for a minute or two, stop and then start again... and after a few minutes...

We have a carrier gas furnace which is only about 5yrs old. The fan is not turning on the unit outside and it has begun making a loud noise but its working fine as far as heating the house. What could be the problem and would it cost a lot to fix. Thanks for any help.

How often do these coils need to be cleaned?

I am looking at furnace for a friend. The furnace will come on with that small fan and the pilot will light. However, the burner will not catch. This unit has a igniter I suspect that the igniter is bad. Is there any way to test it?