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

Your furnace keeps your house warm during the harsh winter months, so it’s annoying when something is off. One frequent issue is a furnace that continually switches on and shuts back off all the time. This problem is known as short cycling. It strains your furnace and could lead to expensive repairs or even early replacement. 

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

1. Dirty Air Filter 

The HVAC filter attracts airborne dust, hair and other substances that could damage the furnace. If you don’t get a new filter regularly, it can become clogged and reduce the airflow. When this occurs, a safety device turns off the furnace to stop overheating. Check the filter, and if it’s dirty, install a new one. Going forward, get 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 reduce airflow and overheat your furnace. Walk around your residence and check for shut or crowded air vents. For adequate system balance and performance, keep all registers open, even in empty rooms. 

3. Dirty Blower Wheel 

The furnace blower has blades that push 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 easiest approach to prevent a dirty blower wheel. If the blades are already dirty, schedule 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. Ensure the thermostat is in 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 impact the temperature reading. If you have a smart thermostat, visit the manufacturer’s site for troubleshooting instructions. 

5. Dirty Flame Sensor 

The flame sensor switches off the gas valve when no burner flame on. The sensor can’t detect the flame if it’s covered in soot, so the gas turns off prematurely and the furnace shuts off. Leave the job of cleaning a sooty flame sensor to an Expert like Service Experts Heating, Air Conditioning & Plumbing. 

6. Oversized Furnace 

When it involves HVAC equipment, oversized isn’t always best. A larger system heats up your residence too quickly, causing unpleasant temperature fluctuations and short cycling. The only way to fix this issue is to schedule new furnace installation

If you attempt the fixes we covered here and nothing has changed, it’s time to contact the Experts at Service Experts Heating, Air Conditioning & Plumbing. We’ll take a look at the situation, diagnose the cause, and provide the necessary work. Our goal is to bring back indoor comfort, energy efficiency and reliable furnace performance for the remainder of the season. And our services are supported by a 100% Satisfaction Guarantee for a year.* For more info about furnace short cycling, or to book HVAC repair, give us a call at 866-397-3787 now! 

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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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