6 Reasons Why Your Furnace Keeps Turning Off and How to Fix It 

Your furnace keeps your family warm during the frigid winter months, so it’s frustrating when something is wrong. One routine complaint is a furnace that endlessly kicks on and shuts back off all the time. This problem is referred to as short cycling. It strains equipment and could cause expensive repairs or even early failure. 

Short cycling can happen for a few reasons. Before you request furnace repair, review the probable causes and how to fix the situation. 

1. Clogged Air Filter 

The HVAC filter traps airborne dust, hair and other substances that could wreak havoc on furnace. If you don’t replace the filter frequently, it can eventually be clogged and reduce the airflow. When this occurs, a safety mechanism shuts off the furnace to avoid overheating. Check the filter, and if it’s dirty, replace it. Going forward, change the filter every 30 to 90 days to keep your furnace from short cycling. 

2. Obstructed Air Vents 

A dirty filter isn’t the only trouble that can reduce airflow and overheat your furnace. Walk around your residence and look for unopened or blocked air vents. For adequate system balance and performance, keep all registers open, even in empty rooms. 

3. Dirty Blower Wheel 

The furnace blower uses blades that distribute air through the ductwork. If they are covered in dirt, the air won’t travel right, leading to overheating and short cycling. Frequently changing the filter is the simplest way to prevent a dirty blower wheel. If the blades are already dirty, book furnace maintenance to have them cleaned. 

4. Faulty Thermostat 

Inspect your thermostat next. This is the brain of your HVAC system and instructs the furnace on what to do. Make sure the thermostat is set to heating mode and auto fan with the desired temperature shown on the screen. Try changing the batteries. Also, check whether the thermostat is in direct sunlight or near a heat source that could affect the temperature reading. If you use a smart thermostat, go to the manufacturer’s site for troubleshooting guides. 

5. Dirty Flame Sensor 

The flame sensor turns off the gas valve when no burner flame is present. The sensor can’t find the flame if it’s coated in soot, so the gas shuts off prematurely and the furnace shuts off. Leave the work of repairing a faulty flame sensor to a pro like Service Experts Heating, Air Conditioning & Plumbing. 

6. Oversized Furnace 

When it comes to heating and cooling equipment, bigger isn’t always best. A larger system heats up your residence too fast, causing intolerable temperature fluctuations and short cycling. The only way to take care of this issue is to schedule new furnace installation

If you try the resolutions we went over here and nothing has changed, it’s time to call in the Experts at Service Experts Heating, Air Conditioning & Plumbing. We’ll examine the situation, pinpoint the cause, and provide the necessary service. Our goal is to bring back indoor comfort, energy efficiency and dependable furnace performance for the rest of the season. And our work is supported by a 100% Satisfaction Guarantee for a year.* For more info about furnace short cycling, or to book HVAC repair, give us a call at 866-397-3787 now! 


*Not applicable to the Advantage Program. See your signed Advantage Program Agreement for full details and exclusions. 100% Satisfaction Guarantee is subject to certain restrictions and limitations as set forth in the applicable Terms and Conditions. 

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