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View Full Version : Furnace only turns on by manual switch


dcomber
Dec 4, 2006, 10:44 PM
Hello,

Im not an HVAC person, but hope to be armed with a little information before calling a professional and not getting charged for any unnecessary charges.

I have a Bryant gas furnace (forced air) that is five years old. I have an electronic/digital thermostat (Honeywell) that controls the furnace (batteries just changed). Recently, I have noticed that when I set the furnace (on auto) to maintain a constant temperature (like 68 degrees), it will say that the furnace is heating (designated by a little flame image on the thermostat) but the furnace is not operating at all. When I go up to the furnace and flick the light switch on and off and goes right back on and heats the house until it reaches 68 degrees and then shuts off. When the temperature in the house goes back under 68 degrees, the furnace does not start again until I turn the switch on and off. I check the circuit breaker and it was fine. Sometimes it works for a few days, but then I have to repeat the process as mentioned above.

I am trying to sell my home, so I hope this nothing majour, just want to make sure I have a good idea of what it is before having the service tech come out and do not get overcharged for something. If anyone can point me in the right direction, I would greatly appreciate it.

labman
Dec 5, 2006, 04:22 AM
I doubt the thermostat has anything to do with it. Next time it fails, jumper the red and white wires and see if the furnace kicks on. If not, it is the furnace, most likely the control board. I paid $300 a few years ago for one for my Bryant furnace.

NorthernHeat
Dec 5, 2006, 02:25 PM
It sounds like the furnace is locking out. Next time it stops running don't turn anythind on or of and check for a blinking code inside the furnace, usually a small red LED light behind a small peek hole of the blower compartment

dcomber
Dec 5, 2006, 02:33 PM
Hello,

Im not an HVAC person, but hope to be armed with a little information before calling a professional and not getting charged for any unnecessary charges.

I have a Bryant gas furnace (forced air) that is five years old. I have an electronic/digital thermostat (Honeywell) that controls the furnace (batteries just changed). Recently, I have noticed that when I set the furnace (on auto) to maintain a constant temperature (like 68 degrees), it will say that the furnace is heating (designated by a little flame image on the thermostat) but the furnace is not operating at all. When I go up to the furnace and flick the light switch on and off and goes right back on and heats the house until it reaches 68 degrees and then shuts off. When the temperature in the house goes back under 68 degrees, the furnace does not start again until I turn the switch on and off. I check the circuit breaker and it was fine. Sometimes it works for a few days, but then I have to repeat the process as mentioned above.

I am trying to sell my home, so I hope this nothing majour, just want to make sure I have a good idea of what it is before having the service tech come out and do not get overcharged for something. If anyone can point me in the right direction, I would greatly appreciate it.
Thanks for your replies, they are greatly appreciated. I called a few professionals today and they both said the same thing, check for the blinking light when it begins to shut down after heating. I just hope it is nothing major, like a $300 control board, but I guess that's how it goes... thanks so much!

NorthernHeat
Dec 5, 2006, 02:49 PM
Most likely it won't be the board.