6 Reasons Why Your Furnace Keeps Shutting Off and How to Take Care of It

Your furnace keeps your house cozy during the frigid winter months, so it’s frustrating when something is wrong. One common situation is a furnace that continuously turns on and switches off again. This problem is referred to as short cycling. It overworks equipment and may result in costly repairs or even earlier than normal failure.

Short cycling can be the result of for a few reasons. Before you schedule furnace repair, consider the possible causes and how to fix the situation.

1. Filthy Air Filter

The HVAC filter catches airborne dust, hair and other substances that could damage the furnace. If you don’t replace the filter often enough, it can eventually be dirty and block the airflow. When this happens, a safety feature shuts off the furnace to stop getting too hot. Check the filter, and if it’s dirty, replace it. Going forward, get a new filter every 30 to 90 days to keep your furnace from short cycling.

2. Obstructed Air Vents

A dirty filter isn’t the only issue that can lower airflow and overheat your furnace. Walk around your residence and be on the lookout for for unopened or crowded air vents. For proper system balance and performance, keep all registers open, even in unused 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 move properly, causing overheating and short cycling. Regularly replacing the filter is the best way to stop 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 instructs the furnace on what to do. Double-check the thermostat is set to heating mode and auto fan with the desired temperature displayed on the screen. Try changing the batteries. Also, check whether the thermostat is in bright sunlight or near a heat source that could affect the temperature reading. If you use a smart thermostat, check the manufacturer’s site for troubleshooting tips.

5. Dirty Flame Sensor

The flame sensor is responsible for turning off the gas valve when no burner flame going. The sensor can’t detect the flame if it’s sooty, so the gas switches off too soon and the furnace turns off. Leave the work of fixing a dirty flame sensor to a pro like Service Experts Heating & Air Conditioning.

6. Oversized Furnace

When it involves heating and cooling equipment, bigger isn’t always best. An oversized system heats up your home too quickly, causing intolerable temperature fluctuations and short cycling. The only way to resolve this issue is to do new furnace installation.

If you go through the resolutions we covered here and you’re still having issues, it’s time to contact the Experts at Service Experts Heating & Air Conditioning. We’ll take a look at 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 work is upheld by a 100% Satisfaction Guarantee for a year.* For more info about furnace short cycling, or to request HVAC repair, reach us at 540-302-8645 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.

chat now widget box