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6 Reasons Why Your Furnace Keeps Switching Off and How to Repair It 

Your furnace keeps your you warm during the harsh winter months, so it’s annoying when something is off. One common issue is a furnace that endlessly kicks on and shuts back off again. This issue is known as short cycling. It overworks your heating system and might result in pricey repairs or even early breakdowns. 

Short cycling can happen for several reasons. Before you schedule furnace repair, read about the possible causes and how to take care of the problem. 

1. Clogged Air Filter 

The HVAC filter catches airborne dust, hair and other debris that could wreak havoc on furnace. If you don’t change the filter frequently, it can become filthy and decrease the airflow. When this happens, a safety mechanism turns off the furnace to prevent overheating. Inspect the filter, and if it’s dirty, get a new one. From now on, change 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 thing that can reduce airflow and overheat your furnace. Walk around your house and check for unopened or obstructed air vents. For adequate system balance and performance, keep all registers open, even in unused rooms. 

3. Dirty Blower Wheel 

The furnace blower uses blades that push air through the ductwork. If they are dirty, the air won’t flow properly, leading to overheating and short cycling. Frequently 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 

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 on 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 influence the temperature reading. If you use a smart thermostat, visit the manufacturer’s site for troubleshooting tips. 

5. Soot-Covered Flame Sensor 

The flame sensor turns off the gas valve when no burner flame on. The sensor can’t sense the flame if it’s covered in soot, so the gas shuts off sooner and the furnace shuts off. Leave the work of repairing a faulty flame sensor to an Expert 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 house too fast, leading to intolerable temperature swings and short cycling. The only way to fix this situation is to schedule new furnace installation

If you try the fixes we mentioned here and nothing has changed, it’s time to call in the Experts at Service Experts Heating, Air Conditioning & Plumbing. We’ll review the situation, pinpoint the cause, and do the necessary work. Our goal is to reintroduce indoor comfort, energy efficiency and reliable 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 schedule HVAC repair, call us at 866-397-3787 right away! 

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*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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