If your furnace is blowing cold air, it could be a sign of a serious problem or could be fixed by the average homeowner.
Your Thermostat Fan is “On”
Thermostats have fans that can be controlled by a toggle on even the most low-tech thermostats. Most have only two different settings, on and auto. “On” means that the fan is constantly circulating air throughout your home, even when your home is not being heated or cooled.
This has some benefits for homeowners, particularly for indoor air quality since the air in your home will cycle through your filters more regularly. However, if you but can cause confusion for some homeowners, who expect their vents to only dispense warm air.
Change Your Air Filter
If you don’t remember the last time you changed your air filter, it’s most likely too dirty. When your air filter becomes clogged, it can restrict airflow, in turn, causing your furnace to overheat. Your furnace will shut off for safety in this scenario and your vents may blow cold air. You should be fine after replacing the filter but monitor your furnace in the next few weeks to ensure that the cold air in your vents isn’t being caused by a more serious issue.
Pilot Light Problems
The pilot light is the small flame that ignites your burners. If it is out that means you have an ignition problem, which explains why you aren’t getting warm air in your vents.
Gas Supply Issues
You may have a problem with your gas supply. Whether you have a leak or your gas line has been turned off, you’ll need to figure out what the possible issue could be.
Your furnace may be blowing cold air because all of the heated air is leaking out of your ductwork. It wouldn’t hurt to check the ducts if the other potential causes do not seem to fit.