Why is My Furnace Blowing Cold Air?

Why is my furnace blowing cold air

If your furnace is operating normally, but cold air is blowing through the vents, there may be a simple fix that will solve the problem.

What follows are a few of the most common reasons a furnace blows cold air.

The thermostat is set incorrectly. Make sure the thermostat is set to “auto” rather than “on”. When the fan on the thermostat is set to “auto”, it will only come on when the furnace is on, instead of running all the time.

The air filter is dirty. If you haven’t changed your air filter, and it is full of dirt and debris, it can restrict the air flow and cause your furnace to overheat. When your furnace overheats, a safety control shuts off the burners to protect your furnace.

That is why we stress the importance of checking and changing your air filter on a regular basis!

The pilot light is out. If you have an older gas furnace, the pilot light may have gone out. We recommend calling a professional HVAC technician or your utility company to make sure it is safely relit. Or if you feel comfortable, follow the manufactures instructions and relight the pilot light yourself.

Other causes:

Leaky ductwork. Large holes and leaks in ductwork can make it feel like your furnace isn’t working properly. Cold air from your attic and basement can get in through the holes in your ducts.

Dirty Sensors. If your furnace starts out warm but then turns cold quickly, your flame sensors could be dirty. A dirty sensor tells the furnace to turn off the burner, which is why it blows cold air after the initial burst of warm air. It is best to call a professional HVAC technician to clean the sensor. Make sure to have annual maintenance performed on your furnace to help avoid this issue in the future.

If your furnace is still blowing cold air after you’ve tried our troubleshooting tips, it is time to call in a professional! The cold air coming from your furnace may be the result of a much more serious issue.

Contact Burkholder’s HVAC today and one of our NATE certified technicians will come to your home and work through a serious of tests to diagnose and get your system up and running as soon as possible.