Furnace Troubleshooting Guide: 8 Common Problems and Fixes

Is your furnace acting up? Whether it won’t turn on or isn’t heating properly, this guide covers the most common furnace problems and what you can do before calling for help.

1. Furnace Won’t Turn On

Check your thermostat settings. Make sure it’s set to “heat” and the temperature is higher than the current room temp. If it still won’t turn on, check the circuit breaker and furnace switch.

2. No Warm Air

If the blower is running but no heat is coming out, you might have a dirty filter, a tripped high limit switch, or an issue with the gas supply. Start by replacing the filter.

3. Furnace Keeps Shutting Off

Short cycling is when your furnace turns off too quickly. It could be caused by a clogged filter, overheating, or thermostat placement. A tune-up can help identify the issue.

4. Strange Noises

Banging, screeching, or rattling could indicate loose parts or a blower motor issue. Turn off the system and call a professional before damage worsens.

5. Pilot Light or Ignition Problems

If your furnace has a pilot light, make sure it’s lit. Newer models use electronic ignition, which can fail due to dirt or faulty components. These repairs should be handled by a technician.

6. Thermostat Isn’t Responding

Check the batteries and connections. If it’s outdated, it may be time to upgrade to a smart thermostat for better accuracy and control.

7. Bad Odors

Musty or burning smells could be dust buildup, while rotten egg smells may indicate a gas leak. If the smell persists, turn off your furnace and contact us right away.

8. High Energy Bills

A sudden spike in your heating bill can point to reduced efficiency. Schedule seasonal maintenance to improve performance and catch small issues early.

Still Having Trouble? Call the Pros

If your DIY furnace troubleshooting doesn’t solve the issue, Aegis Heating & Air can help. Our experienced HVAC technicians diagnose and repair all furnace brands.

Schedule Furnace Repair or Maintenance Today

Call (385) 250-0687 or book an appointment online for reliable furnace service anywhere in our Utah service area.