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Why Is My Furnace Blowing Cold Air?

Girl in a white hat and blue vest standing with a mug of tea.

Did you finally turn your furnace on this winter only to have cold air blowing out of your vents? Or did your furnace stop working just when you started to need it most? There are a few reasons your furnace may be blowing cold air, and there a few things to check before you need to worry too much. At A-1 Mechanical, we are here in Las Vegas, NV, to keep you warm and toasty this winter. If you are having problems with your furnace, check these things first and then call us for help.  

1. Check Your Thermostat’s Settings

Be sure your thermostat is set on the correct setting. If it is set to ON, the blower will run continuously even when the furnace is not heating the air. The air coming through the vents will seem cool because it is room-temperature air. Turn your thermostat to AUTO, then the fan will only run when the furnace is heating, and you will not get tepid or room-temperature air.  

2. Change the Air Filter

A dirty air filter will cause your furnace to overheat. It restricts the airflow in and out of your furnace, which can cause this issue. If it does overheat, the safety control will shut off the burners, causing the fan to blow cool air through the house versus heated air.

3. Check the Pilot Light

Your furnace may be blowing cold air because the pilot light has gone out. It is a simple fix—just relight the pilot. If it continues to go out after you relight it a few times, then you should contact us to come out. This is indicative of a bigger problem requiring professional help.  

4. Reboot Your System

If you have a modern furnace, you probably have one controlled by a computer. Sometimes there is simply a glitch in the system, and it needs a simple reset—the same way you would restart your computer or phone. If you turn off your furnace for 30 seconds and then turn it back on, it may reset itself and begin functioning correctly. If it doesn’t start working the way it should after you have restarted it, call one of our HVAC professionals to diagnose and repair the issue expediently for you.  

5. Examine Your Ductwork

The older your ductwork is, the more likely it is to be damaged or leaky. If it does turn out to be damaged or leaky, air can be escaping before it gets to the desired living areas. Inspect the ductwork yourself, but it is possible you may not be able to visually detect the rips or tears causing your leak. It is best to call us at 702-363-6222 for an in-depth ductwork inspection.

If none of these troubleshooting suggestions get your furnace up and running again, unfortunately you may have a bigger problem. Contact our A-1 Mechanical professionals today, and we would be happy to come to your home and repair any problem you might be having!

Need HVAC Service?

Contact the experts at A-1 Mechanical.

Call us at 702.363.6222!