7 DIY Gas Furnace Troubleshooting Tips

When the furnace sputters or shuts off in the middle of winter, it’s a stressful situation. You want to get it fixed immediately, but you may be skittish about attempting DIY repairs on a furnace that runs on potentially dangerous gas fuel.

There are some simple, safe DIY gas furnace troubleshooting steps that just about anybody can start with to try to resolve efficiency or heating problems. Try these tips and then call your local furnace repair specialists if you get stuck and need more advanced help.

1. Check All the Furnace Settings

Before getting your hands dirty or calling for service, do take a moment to check all of the settings on the furnace and thermostats. If your furnace is blowing cool air, check if it’s set to “auto” and if so, change it to “on.” The auto setting makes some furnaces run constantly, so it blows cooler air when the burners are off.

2. Replace the Air Filter

Dirty filters most often cause dissatisfying furnace performance and efficiency drop-offs. Err on the side of caution and clean or replace your filter a bit more frequently than you currently do. Don’t just wipe down disposable filters to prolong their life; they really stop working once the material has been used.

3. Look for a Tripped Circuit Breaker

Check your electrical panel for a tripped breaker if the furnace won’t turn on at all or if a wired (non-battery) thermostat is off. If it keeps tripping, you may have a serious electrical problem that a professional should fix.

4. Level the Thermostat

Older mechanical thermostats must be level on the wall. Furnaces that cycle on and off too frequently may be due to a confused thermostat. If this problem continues after the thermostat is level, you can call an HVAC technician to fine-tune the inner parts of the thermostat.

5. Check the Blower Motor and Belts

These furnace parts can cause squeaky noises and may contribute to a furnace shutting off soon after starting up. More advanced DIY fans can try lubricating the motor (with an appropriate lightweight oil) or tightening or replacing the belts.

6. Unblock Clogged Vents and Flues

Check the chimney flue and any other vents for obstructions. Outside exhaust vents may be home to a bird’s nest, dead leaves, or other debris. Blocked vents lower the furnace’s energy efficiency and may trigger an automated shutdown.

7. Open All Ductwork Grilles

Cold rooms or inconsistent temperatures throughout the home may be due to closed registers or grilles. Certain combinations of closed vents can negatively impact the proper airflow that your furnace needs to work properly.

When to Call for Gas Furnace Repair

If you’re still scratching your head or have identified an issue that calls for tools and experience you do not have, be safe and call the pros. We provide fast service and honest repair recommendations for people in the St. Louis area. Call 314-845-5900 or request an appointment online to get started.