Cold air running from vent - thermostat at 70

steveex

Need more info, what kind of system? Hydro coil, furn.

Danni

Cold air coming from vent - thermostat at 72

I recently turned the heat on for the winter. I set it to 65 and it will run but it runs very cool air, it's not until I turn the air up to 72 that warm air will pump out of the vents but it eventually will run cold and it just continues to run...if I try to turn it off it takes at least five minutes and then it will not cut on again unless I put the thermostat to 70 (I have a mercury thermostat) Is it wiser to go to a digital one?

Danni

I'm not sure what you mean - I'm a first time condo owner. I do know that it's central heat (electric)....How could I check this for you. I believe there is a furnance (in one of the storage closets) - sorry

louise_3

cold air

I have almost the same problem. My heat come out from the vent for about 10mins. The just cool air. I have the fan set on auto. Even when I turn the system to off it still runs. All I know is that I have a furnace in the attic and it worked last year. Help

zeke

You have your fan switch set to "on" which makes it run continuously regardless of whether there is a call for heat or not. Use the "auto" setting which will blow air only when there is a heat call from the thermostat

zeke

You may have a furnace temperature limit switch failure which after the furnace shuts down senses the temperature at the furnace heat exchanger and opens at some cooler temperature.
When working properly it then shuts off the blower. Yours may be stuck closed and keeps the blower on.
Another reason is that the last serviceman may have used the furnace override switch for testing during servicing and forgot to restore it afterwards.
In either event call your service person to fix it.

Phil_17

Sounds like you have a heat pump...

I lived in a townhouse once-upon a time, and that's what heat pumps do.

The air coming out of the vents is never supposed to be "warm", it's just warmer than the air in the room. The motion of the air makes it feel cold though it is probably 5-10 degrees warmer than the ambient. If it really feels warm, then you have just kicked it into "recovery" mode which just turns on resistance heaters (think a hair dryer) and makes your electric meter spin like a child's toy top :-(

The five minutes to restart is a typical safety put on heat pumps and air conditioners.

paul_91

electric

does this furnace have a electric water heater right under it?.....IF SO ,IF YOUR CALLING FOR HOT WATER ONLY ONE HEATER WILL BE ENERGIZED IN THE FURNACE... UNTIL THE WATER HEATER IS SATISFIED WITH HOT WATER. ALSO WHAT KIND OF FURNACE IS IT?