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Furnace Not Heating
Common reasons for your furnace not heating
The most common reasons for your furnace not heating are power supply issues, thermostat settings, or ignition system failures.
25% of the time it's the Power Supply Issues
20% of the time it's the Thermostat Settings
18% of the time it's the Ignition System Failures
37% of the time it's the Something else
Schedule your furnace repair now!
We can help! Our certified technicians repair all brands and models of furnaces. We can fix yours no matter where you bought it.
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Gas Furnace Not Heating – Troubleshooting and Repair
When your gas furnace won’t heat, it’s often caused by one of three common problems: no power, no ignition, or thermostat issues. Before setting up a repair visit, try these quick steps.
1. Check Furnace Power
A furnace without power can’t start the blower or heat your home.
- Make sure the furnace power switch (near the unit) is turned ON.
- Check your home’s circuit breaker panel and reset any tripped breaker.
- If your system uses a fuse instead of a breaker, replace a blown fuse.
2. Verify Thermostat Settings
- Set the thermostat to HEAT mode and raise the temperature setting several degrees above room temperature.
- If your thermostat uses batteries, replace them.
- If the display is blank or unresponsive, that’s likely the reason your furnace won’t start. Shut off the house circuit breakers for your furnace and check the thermostat wiring connections. If the wiring connections are okay, schedule service.
3. Check the Igniter or Pilot Light
- Older furnaces use a standing pilot light—make sure it’s burning. Follow manufacturer instructions to relight it safely if it’s out.
- Newer models use electronic ignition. If the furnace clicks but never ignites, the igniter or flame sensor may need service.
If your furnace still isn’t blowing hot air after these checks, it’s time for a professional repair.
Schedule Trusted Furnace Repair Near You
Sears Home Services repairs all major gas furnace brands and models.
Furnace brands we service include Carrier, Bryant, Trane, Lennox, York, Rheem and more.
Our nationwide service network provides furnace repair in every major metro area across the country including:
- New York
- Los Angeles
- San Diego
- Dallas
- Houston
- Atlanta and more
Our licensed technicians can quickly diagnose the problem—whether it’s a bad igniter, faulty control board, dirty flame sensor, or gas valve issue—and get your system heating again fast.
- Expert furnace repair technicians
- Same-day and next-day appointments available
- All repairs backed by the Sears satisfaction guarantee
Call 1-800-469-4663 or schedule your furnace repair online today to get your heat restored quickly.
Frequently Asked Questions
Why is my gas furnace blowing cold air instead of heat?
If your furnace runs but blows cold air, the burners may not be lighting. Check your air filter and thermostat settings first. If those are fine, the igniter or flame sensor may need service.
Can a dirty air filter stop my furnace from heating?
Yes. A clogged filter restricts airflow and can cause the furnace to overheat and shut off. Replace the filter and restart the system.
How do I know if my furnace igniter is bad?
If you hear clicking but no ignition, or if the furnace lights and shuts down quickly, the igniter could be cracked or worn out. A technician can test and replace it.
How fast can Sears Home Services fix my furnace?
Sears offers same-day and next-day appointments in most areas. Schedule online or call to arrange fast, professional gas furnace repair near you.
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