Why Is My Furnace Blowing Cold Air?

Few things are more frustrating than turning on your furnace and feeling cold air coming from the vents. Don’t panic—there are a few common reasons this happens, and some are easy to fix.

1. Thermostat Settings

Sometimes the problem is as simple as your thermostat being set to “ON” instead of “AUTO.” In the ON setting, the fan runs constantly, even when the furnace isn’t heating. Switch it to AUTO and see if that fixes the issue.

2. Dirty Air Filter

A clogged filter restricts airflow, which can cause the furnace to overheat and shut off the burners. If you haven’t changed your filter in a while, swap it out and check again.

3. Pilot Light or Ignition Problems

For older furnaces, a blown-out pilot light can prevent heating. Newer systems may have electronic ignition that fails over time. Either way, this usually requires a professional repair.

4. Ductwork Leaks

Leaky or disconnected ducts can pull in cold air from attics, basements, or crawl spaces. Not only does this make your home less comfortable, but it also wastes energy.

5. Bigger Mechanical Issues

If none of the above solve the problem, you may be dealing with a faulty blower motor, gas supply issue, or cracked heat exchanger—all of which require a trained technician.

👉 Don’t suffer through the cold! If your furnace is blowing cold air, our affordable furnace repair services will quickly get your system back on track—at prices much lower than the competition. [Schedule your service today].