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

Your furnace keeps your family comfortable during the frigid winter months, so it’s disconcerting when something isn’t quite right. One routine issue is a furnace that endlessly switches on and turns off again. This operating error is called short cycling. It overworks your heating system and may cause expensive repairs or even earlier than normal breakdowns.

Short cycling can be the result of for several reasons. Before you book furnace repair, research the possible causes and how to take care of the problem.

1. Dirty Air Filter

The HVAC filter traps airborne dust, hair and other pollutants that could damage the furnace. If you don’t get a new filter frequently, it can become filthy and reduce the airflow. When this happens, a safety mechanism turns off the furnace to prevent getting too warm. Check the filter, and if it’s dirty, install a new one. Going forward, replace the filter every 30 to 90 days to stop 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 home and be on the lookout for for unopened or blocked air vents. For recommended system balance and performance, keep all registers open, even in unoccupied rooms.

3. Dirty Blower Wheel

The furnace blower consists of blades that distribute air through the ductwork. If they are dirty, the air won’t flow correctly, causing overheating and short cycling. Regularly putting in a new the filter is the best method 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 core of your HVAC system and gives the furnace instructions 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 replacing 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 guides.

5. Soot-Covered Flame Sensor

The flame sensor is responsible for turning off the gas valve when no burner flame is present. The sensor can’t sense the flame if it’s sooty, so the gas shuts off too soon and the furnace shuts down. Leave the job of cleaning a faulty flame sensor to an Expert like Service Experts Commercial HVAC.

6. Oversized Furnace

When it involves home comfort equipment, bigger isn’t always best. A larger system warms up your residence too quickly, causing intolerable temperature fluctuations and short cycling. The only way to resolve this issue is to schedule new furnace installation.

If you try the resolutions suggested here and you’re still having issues, it’s time to reach the Experts at Service Experts Commercial HVAC. We’ll review the situation, figure out the cause, and do the necessary work. Our priority is to reintroduce indoor comfort, energy efficiency and trustworthy furnace performance for the remainder of the season. And our services are upheld by a 100% Satisfaction Guarantee for a year.* For more information about furnace short cycling, or to request HVAC repair, reach us at 289-201-2346 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.

Contact Us