Furnace Blowing Cold Air?
Try these 3 fixes before calling a tech. Most are free and take under 5 minutes.
Check the Thermostat Fan Setting
If your thermostat fan is set to "ON" instead of "AUTO", the blower runs constantly—even when the furnace isn't heating. This pushes room-temperature air through the vents, making it feel cold.
The Fix
Set your thermostat fan to AUTO. The blower will only run when the furnace is actively heating.
Inspect Your Air Filter
A clogged filter restricts airflow, causing the furnace to overheat. When that happens, the safety limit switch shuts off the burner—but the blower keeps running, pushing cold air.
The Fix
Check your filter. If you can't see light through it, replace it. Wait 30 minutes for the furnace to cool down, then try again.
Verify the Pilot Light or Igniter
If your pilot light is out or the electronic igniter has failed, the burners won't fire. The blower may still run (trying to distribute heat that isn't there).
The Fix
For pilot lights: Follow manufacturer instructions to relight. If it won't stay lit, you likely need a new thermocouple.
For electronic ignition: This usually requires a tech to diagnose and replace.
Still Blowing Cold?
Could be a faulty limit switch, gas valve issue, or ductwork problem. These need a professional diagnosis.