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November 20, 2023

Why Does My Furnace Keep Tripping the Reset Button?

Does your furnace keep shutting off before it reaches the desired temperature? It could be a problem with your reset button, causing you to wonder, “Why does my furnace keep tripping the reset button?”

Keep reading to discover what the experts at furnace installation in Greenwood, IN, suggest for troubleshooting your furnace, including what the reset button does and why it trips.

What Is the Furnace Reset Button?

The furnace reset button is a safety feature that shuts down the system when it exceeds the maximum suggested temperature. This also prevents the circuit breaker from tripping.

You can usually find the reset button in the blower compartment near the blower motor, and you can identify it by its distinct red or yellow color. While you shouldn’t worry about the reset button tripping occasionally, if it does so continually, it signifies a problem.

Common Reasons the Reset Button Trips

The following four factors are the most common causes of a frequently tripped reset button. You can use these to help determine the problem and seek professional assistance for the right solution.

1. Overheating

Overheating is the most common reason for a frequently tripping reset button. The problem often occurs in furnaces installed without good ventilation to facilitate proper airflow.

When the heat has no place to escape, it forces the furnace to exceed safe temperatures. Since this is the basic function of the reset button, it means it’s working correctly, but you should fix your furnace’s ventilation problem.

2. Dirty Air Filter

A dirty air filter can cause your reset button to trip prematurely because it’s often an additional cause of overheating in your furnace. The air filter purifies the air circulating through your home, naturally accumulating dust and other particles over time. Eventually, this restricts the amount of warm air flowing from your furnace.

Much like the effects of poor ventilation, this causes increased heat within the furnace and forces the reset button to trip to prevent serious fire hazards or other dangerous complications with your appliance.

3. Lack of Fuel

If you’re asking, “Why does my furnace keep tripping the reset button?” consider the possibility you’re out of fuel. While electric furnaces won’t run out of fuel, the problem often occurs in oil-based furnaces. That’s because the oil furnace draws its fuel from a tank located in your home or on your property, and you must contact your supplier to refill the tank.

Gas furnaces can also lack fuel, though this occurs more often as a supply issue from your utility company rather than empty storage. If you have a gas furnace, the reset button can also trip if you have improperly closed gas valves. This valve regulates the flow of natural gas into the furnace, and if it closes unnecessarily, it can trip the reset button.

4. Problematic Flame Sensor

Your flame sensor is another safety device determining whether your furnace has a lit flame and is burning off the natural gas. It prevents the toxic substance from filling your home by closing the gas valve when there’s no flame present.

Because of all the dust in your furnace, the flame sensor can accumulate debris, and a dirty flame sensor loses its ability to sense a flame within your furnace. To prevent safety issues, the system trips the reset button.

Maintaining Your Furnace

You can help avoid reset button tripping by practicing good maintenance habits for your furnace. 

Annual Inspections

To ensure your furnace lasts as long as possible and has a low chance of needing serious repairs, schedule maintenance from a certified HVAC technician at least once a year. The best time is in the fall, right before the season you use your furnace the most.

During the annual inspection, the technician can clean your furnace, which prevents many of the problems that cause a frequently tripping reset button.

Regular Air Filter Replacement

A dirty air filter can cause various problems beyond a tripped reset button, so regularly replacing it is one of the most important maintenance tips. Check your filter at least every 30 days, and clean or replace it as necessary, depending on the type of filter your furnace uses.

If you smoke, have pets that shed, or live in a polluted area, you should check your air filter every two weeks to avoid more severe issues.

Moderate Your Usage

The less you use your furnace, the longer it lasts and the fewer problems it experiences. Consider purchasing an energy-efficient furnace so you can run it less frequently. You should also set your thermostat to 68 degrees in the winter so it runs less while still keeping you safe and comfortable.

How To Fix a Tripped Reset Button

You can attempt to reset the furnace yourself, but calling a professional is always safer. Use the following process to start it again, skipping step four if you have an electric furnace:

  1. Confirm the pilot light isn’t lit.
  2. Turn your thermostat as low as possible.
  3. Turn off the furnace from the circuit breaker.
  4. Shut off your gas or oil supply.
  5. Relight the pilot light.
  6. Return power from the circuit breaker and open access to your fuel supply.
  7. Hold the reset button for at least 30 seconds.
  8. Turn your thermostat back up to your desired setting.

If you’re concerned about safety, don’t feel embarrassed. While complications are rare, addressing furnace issues without proper training always presents a safety risk. Calling a professional is always the best option.

Contact the HVAC Specialists for Help

Now you know the answer to “Why does my furnace keep tripping the reset button?” Complete Comfort Heating, Air & Plumbing can help you with all HVAC issues. Whether your furnace is making noise or your air conditioner blows hot air, our knowledgeable and friendly experts can always help.

To schedule an appointment or for answers to any questions you might have regarding a tripping reset button or other furnace-related issues, call us at (317) 678-7092.