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

Your furnace keeps your family cozy during the chilly winter months, so it’s annoying when something isn’t quite right. One common issue is a furnace that endlessly turns on and shuts back off again. This operating error is called short cycling. It stresses equipment and could lead to expensive repairs or even early breakdowns. 

Short cycling can happen for varying reasons. Before you request furnace repair, read about the potential causes and how to resolve the situation. 

1. Filthy Air Filter 

The HVAC filter attracts airborne dust, hair and other debris that could wreak havoc on furnace. If you don’t get a new filter often enough, it can get filthy and reduce the airflow. When this takes place, a safety feature turns off the furnace to avoid getting too warm. Check the filter, and if it’s dirty, replace it. From now on, get a new filter every 30 to 90 days to prevent your furnace from short cycling. 

2. Clogged Air Vents 

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

3. Dirty Blower Wheel 

The furnace blower consists of blades that move air through the ductwork. If they are covered in dirt, the air won’t travel correctly, leading to overheating and short cycling. Frequently replacing the filter is the simplest method to avoid a dirty blower wheel. If the blades are already dirty, request furnace maintenance to have them cleaned. 

4. Faulty Thermostat 

Check your thermostat next. This is the brain of your HVAC system and tells the furnace what to do. Make sure the thermostat is on heating mode and auto fan with the desired temperature shown on the screen. Try replacing the batteries. Also, check whether the thermostat is in direct sunlight or near a heat source that could influence the temperature reading. If you rely on a smart thermostat, check the manufacturer’s site for troubleshooting instructions. 

5. Soot-Covered Flame Sensor 

The flame sensor is responsible for turning off the gas valve when no burner flame going. The sensor can’t sense the flame if it’s covered in soot, so the gas switches off too soon and the furnace shuts off. Leave the work of cleaning a faulty flame sensor to a professional like Service Experts Heating, Air Conditioning & Plumbing. 

6. Oversized Furnace 

When it comes to heating and cooling equipment, oversized isn’t always right. A bigger system warms up your home too fast, causing intolerable temperature swings and short cycling. The only way to take care of this situation is to request new furnace installation

If you try the resolutions suggested here to no avail, it’s time to call in the Experts at Service Experts Heating, Air Conditioning & Plumbing. We’ll examine the situation, pinpoint the cause, and do the necessary repair. Our goal is to restore indoor comfort, energy efficiency and trustworthy furnace performance for the remainder of the season. And our repairs are supported by a 100% Satisfaction Guarantee for a year.* For more info about furnace short cycling, or to schedule HVAC repair, reach us at 866-397-3787 right away! 


*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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