Why Is My Furnace Blowing Cold Air?
A furnace blowing cool or cold air instead of heat has a handful of common causes. Many are simple to check first.
Common Causes
- Thermostat fan set to on, so it blows air even between heating cycles
- Dirty flame sensor causing the burners to shut off
- Overheating from a dirty filter, tripping a safety limit
- Pilot light out or a failed igniter on older systems
- Low gas supply or a closed gas valve
What You Can Check Yourself
- Set the thermostat fan to auto instead of on
- Replace a dirty filter
- If you have a pilot light and it is out, follow the furnace instructions to relight it, or call us
When to Call Air Plus Heating
If the quick checks above do not solve it, the problem needs a trained technician. Air Plus Heating has served Utah County since 1982 with honest pricing, free estimates, and same day and 24/7 emergency service. Learn more about our furnace repair in Utah County, or see all of our HVAC troubleshooting guides.
Related Questions
Why Is My Furnace Blowing Cold Air?
A furnace blowing cold air is often caused by the fan being set to on instead of auto, a dirty flame sensor, an overheated furnace that shut off the burners, or a pilot or igniter problem. Set the fan to auto first, then call a technician if it keeps blowing cold.
Why does my furnace blow cold air then warm?
If the fan is set to on, it blows room temperature air between cycles. Switching to auto usually fixes it. If not, the burners may be shutting off early.
Is a furnace blowing cold air dangerous?
Usually not, but if you smell gas, leave and call your gas company. For a no heat call in Utah County, we offer same day and emergency service.
Need HVAC Help in Utah County?
Call (801) 362-5115 for same day and 24/7 emergency service, or request a free estimate.