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

Your furnace keeps your family comfortable during the frigid winter months, so it’s annoying when something isn’t quite right. One common issue is a furnace that endlessly switches on and switches off all the time. This operating error is referred to as short cycling. It overworks your heating system and may cause pricey repairs or even earlier than normal replacement.

Short cycling can be the result of for several reasons. Before you request furnace repair, review the likely causes and how to take care of the problem.

1. Filthy Air Filter

The HVAC filter traps airborne dust, hair and other pollutants that could wreak havoc on furnace. If you don’t replace the filter frequently, it can eventually be filthy and block the airflow. When this occurs, a safety feature turns off the furnace to prevent overheating. Pull Out the filter, and if it’s dirty, install a new one. From now on, install a new filter every 30 to 90 days to keep your furnace from short cycling.

2. Blocked Air Vents

A dirty filter isn’t the only trouble that can restrict airflow and overheat your furnace. Walk around your house and be on the lookout for for shut or crowded air vents. For proper system balance and performance, keep all registers open, even in empty rooms.

3. Dirty Blower Wheel

The furnace blower has blades that distribute air through the ductwork. If they are caked with dirt, the air won’t flow correctly, leading to overheating and short cycling. Routinely changing the filter is the simplest method to avoid a dirty blower wheel. If the blades are already dirty, schedule furnace maintenance to have them cleaned.

4. Faulty Thermostat

Inspect your thermostat next. This is the cortex of your HVAC system and gives the furnace instructions on what to do. Double-check the thermostat is on heating mode and auto fan with the desired temperature showing on the screen. Try changing 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, visit the manufacturer’s site for troubleshooting instructions.

5. Sooty Flame Sensor

The flame sensor switches off the gas valve when no burner flame going. The sensor can’t detect the flame if it’s sooty, so the gas shuts off too soon and the furnace shuts down. Leave the job of cleaning a sooty flame sensor to an Expert like Stark Services.

6. Oversized Furnace

When it involves home comfort equipment, oversized isn’t always better. A bigger system warms up your home too fast, creating intolerable temperature changes and short cycling. The only way to fix this issue is to request new furnace installation.

If you attempt the resolutions suggested here to no avail, it’s time to reach the Experts at Stark Services. We’ll take a look at the situation, pinpoint the cause, and provide the necessary repair. Our priority is to bring back indoor comfort, energy efficiency and trustworthy furnace performance for all season long. And our repairs are supported by a 100% Satisfaction Guarantee for a year.* For more details about furnace short cycling, or to schedule HVAC repair, reach us at 817-668-6689 today!


*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.