How to Troubleshoot Your Furnace After a Power Outage

Have you ever had the power go out on a cold winter day, only to find that your furnace isn’t working after the power’s been restored? It’s fairly common to need to restart your furnace after an outage, even if the power was out for only a brief period of time. If hitting the reset button doesn’t do the trick, there are a few simple steps you can take to troubleshoot the issue before placing a service call. 

A Note on Safety

If you see standing water in your home, don’t attempt to examine or fix your furnace—or any other electrical problems. This could be a serious safety hazard! It’s also likely that you’ll need to have your furnace replaced. Give us a call, and our technicians will handle the issue. 

Furnaces that are over 20 years old can also be dangerous because they rely on manually controlled pilot lights. Even minor issues with older furnaces can cause dangerous carbon monoxide to build up in your home. Older furnaces can also cause house fires due to issues with the pilot light, gas line leaks, or poor ventilation. If your furnace is between 16-20 years old, don’t attempt to inspect or repair it yourself. 

Steps for Troubleshooting Your Furnace

Here are five steps to take when your furnace refuses to turn on after a power outage. Keep in mind that if the outage was caused by construction in your neighborhood, the gas or power lines may have been damaged. Those will need to be repaired by the utility company before your furnace will work properly. If the outage was caused by a lightning strike, the problem could be a blown fuse, which will need to be professionally repaired.  

  • Check the Control Panel

Check your furnace’s control panel. If it’s flashing an error message, it will need to be repaired. 

  • Check the Furnace Safety Lock

When you reset your furnace, make sure to hit the button only once. If you repeatedly hit the button in quick succession, it will engage the safety lock. The safety lock could also cause your furnace to lock up if you’ve had repeated power outages. 

  • Check Your Thermostat

If your thermostat is off, try turning it on and setting it to heat or the automatic fan setting. If the thermostat is already on, restart it. Make sure you’ve turned the temperature up high enough that it will start the furnace. 

If you have a newer thermostat and the power outage lasted more than five minutes, the thermostat may have automatically reset. If the power was out for a long time, the thermostat may have automatically reset to the factory default. If this is the case, you’ll need to consult your owner’s manual to reprogram it—or give us a call and we’ll handle it! 

  • Check Your Breaker Panel

Power outages can trip breakers, but they’re very easy to reset. All you need to do is turn the breaker off and then turn it back on. If your panel doesn’t have labels, most furnaces use a 15A circuit. Locate the breakers marked 15A and see if any of them are tripped. If you have a heat pump, you’ll need to check both the indoor and outdoor panels to reset the breakers. 

  • Check Your GFI Outlets

If your furnace has been installed over the past 10 years, it may be connected to a GFI outlet, especially if your basement is at risk of water damage. Power outages can cause these outlets to trip, so make sure to examine each one that’s near or attached to the furnace. If you find any that have been tripped, press the reset button on the GFI outlet.

If you’ve completed these steps and your furnace still doesn’t turn on, it’s time to contact the experts at PECO! Our 24/7 answering service is ready to take your calls whenever you need assistance with your HVAC system. Contact us at (864) 639-2424 or send us a message through our online form.