Furnace Keeps Tripping Breaker: Troubleshooting Tips

Even though you have a gas furnace, it needs electricity to operate. The furnace control board, furnace blower motor, furnace blower fan, and gas valve all use electricity. If the furnace breaker trips and you reset it and the furnace begins working again normally, you should be fine. There may have been a power surge or spike from a thunderstorm or an issue with the electrical grid.

However, when the furnace circuit breaker keeps tripping after a reset, there is a more serious, underlying issue that needs to be fixed. Don’t keep resetting your furnace breaker. Circuit breakers are safety devices that help prevent house fires. They trip/flip when they detect a dangerous electrical issue.

So, now that you know this is a serious issue you shouldn’t ignore, let’s look at the common causes of a furnace tripping the circuit and solutions for the problem.

Your furnace needs good airflow to operate efficiently. If it doesn’t get enough air, that forces it to work harder and run longer, which can cause the furnace to pull more electrical current than normal. That can lead to a tripped breaker. The most common airflow issues are clogged filters, blocked supply registers, and blocked return air vents.

Clogged ducts or leaky air ducts can also disrupt airflow and cause the furnace to work harder and run longer, with a tripped breaker as the result.

The solution: Check the furnace filter and change it if it’s dirty. Get in the habit of doing that every 30-90 days, depending on the air filters you use. Make sure curtains, rugs, and furniture are not blocking supply registers or return air vents.

Ask your preferred HVAC professionals to evaluate your air ducts for clogs or leaks. Air duct cleaning or duct sealing may solve the problem. 

In most homes, the furnace is on a dedicated circuit, but in some older homes, the furnace may be on a shared circuit. Running your furnace and another electrical device such as a power tool on the same circuit can trip the circuit breaker.

The solution: For a short-term solution, don’t use the outlet on the shared circuit when the furnace is running. For a long-term solution, put the furnace on a dedicated circuit - either a new circuit or by moving the other outlets to a different circuit. We recommend using a licensed electrician to do electrical work.

The furnace blower motor wiring can wear down and lead to arcing and short circuits or ground faults, which will trip the furnace breaker. Other furnace parts that use electricity may also malfunction, with the same result.

The solution: Call for furnace repair. A trained HVAC technician will troubleshoot your furnace and replace any worn-out parts or wiring.

The problem may not be with your furnace at all. You may have a bad furnace circuit breaker or a faulty electrical panel. If you have an older home, your electrical panel may be inadequate for the home. 

The solution: Depending on the problem, an HVAC technician can replace a furnace circuit breaker, but you would need a licensed electrician to handle an electrical panel upgrade. Your HVAC company may have someone on staff or can make a recommendation.

Take care of your furnace if you want it to keep your home warm and cozy. Practice regular furnace maintenance to keep your furnace running when you need it. To ensure good airflow, change the furnace filters regularly - every 30-90 days depending on the quality of the air filter and if you have pets. 

Check out our filter maintenance guide for some helpful tips. 

Just like you take your car or truck in for an oil change or tire rotation, you should schedule a yearly furnace tuneup each fall. This can help ensure that your furnace operates safely and efficiently. 

During the service visit, the HVAC technician should:

• Clean and lubricate the furnace blower motor and other components
• Inspect and tighten electrical connections
• Inspect the gas valve, burners, and ignition system
• Test and calibrate the thermostat
• Test the furnace operation
• Clean the condensate line if applicable
• Make minor repairs or replace worn or failing parts

Many HVAC companies offer yearly HVAC maintenance plans that include fall and spring tune-ups for your heating and cooling systems. They reach out to you to schedule service. You might also be placed on a priority list for HVAC repair, which can be a big deal if your furnace or AC goes out during extreme weather conditions.

Help ensure your furnace is always heating your home when you need it. If you have a Trane smart thermostat, opt into Trane Diagnostics for peace of mind. Use the Trane Home App to give your dealer remote monitoring capabilities.  Your Trane smart thermostat sends about your HVAC system in real-time to your dealer, alerting them to any issues, even when you’re on vacation. 

They can run troubleshooting tests to identify the issue(s). In some cases, they can solve the problem remotely. In this situation, you would grant them one-time dealer remote access (DRA). 

If they need to schedule an on-site service call, the technician will arrive with the knowledge gained from remote access. This enables shorter service calls and ensures the technician has the proper replacement parts. 

A Content Writer with Trane Technologies, Anne Fonda researches topics and writes for Trane® and associated residential HVAC brands. She works in collaboration with Trane Technologies subject matter experts, offering easy-to-understand, informative content on complex topics. Her goal is to help consumers make informed decisions on the products and services they need.

She has written for HVAC and other service provider websites for over 16 years. Before transitioning to web content writing, Anne had a 14-year stint as an award-winning journalist. She graduated cum laude from the University of Missouri-Columbia School of Journalism. When she’s not working, Anne enjoys playing word games, reading, gardening, spending time with family, and visiting gardens and museums.

Expert review by Kimberly Sexton, Senior Systems Engineer

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