Why Is My Furnace Blowing Cold Air?

Try changing the filter!

Try changing the filter

Hm, so perhaps it's not just my imagination or intolerance that's thinking my new furnace is blowing more cold air than heat. I know it wasn't air conditioning I paid for!!

Thank you for your advice.

The thermostat works.  I can hear the furnance kick on - but then it kicks on too fast.  If that makes sense.  Normally, I will hear it, I guess heating the air, then it will begin blowing warm air.  Now, as soon as I turn the termostat on, the furnace begins right away-blowing cold air!!  Of course, it is the coldest day and night - I think ever in the Raleigh NC area!!  

I have a gas fireplace that is working - thankfully.  So, gas is coming into the house. The thermostat and the furnance seem to be working.  But it is getting later - and the sun is going down.  The good news is I guess - at least this weekend it is supposed to be in the 70's!!!!   Crazy ....

If you just turn it on it will do this till it warms up and it is on for a while.  Some do and some do not.  If it persists try changing your filter and then maybe fuses, and see if your thermostat takes batteries and change them if they do.  You can check the wiring and other things for burnt wires.  If you can't figure it out ask a neighbor or a friend or hire someone to come out.  Be careful.

You may have a broken heater coil or if you have been running your heat a lot here lately, it could have frozen your condenser and evaporater. Turn it off, run the ac  for 30 min and then try it.if that does not work, call a professional.

My gas furnace had this problem recently. IT started like an intermittent problem until 3 weeks  and then completely cold air no matter what I do. I called the professionals and they came out/ tested and it was the heater core.it caused me $600.00 bucks including labour and parts. I hope your furnace will be cheaper.

Gas furnace downstairs is blowing cold air, upstairs furnace working fine.  Blower is working.  Thermostat is working.

There could be a couple concens, first one is, the fan may have got switched to run/on. Second one could be you have an issue with the pilot light, that keeps the flame available for the furnace to use when the furnace is called on to produce heat.

Light it or pay your gas bill then light it

Just call the professional instead of trying to do this yourself if you don't know anything about this. You really don't want to have a gas leak, and light that thing. For your health and safety, call the professional. Hope this helps, good luck to you.