Furnace Only Running For A Few Minutes At A Time? Common Causes

Posted on: 25 February 2020


Few things can stress a homeowner like a furnace that shuts off only a few minutes after it fires up in the dead of the winter. After all, your furnace should fire up and run consistently for as long as it needs to in order to warm your house to the thermostat temperature. However, there are a few common reasons why your furnace might only run briefly before it shuts right back down again. Here are a couple of things to check when you're trying to determine if your furnace needs repair.

Faulty Flame Sensor

Your furnace flame sensor is a crucial part of the unit's operation. It's designed to monitor the presence of the flame in the burner. When the furnace turns on but the flame doesn't fire, the flame sensor shuts the gas supply off to prevent gas buildup that can lead to hazardous conditions.

However, sometimes the flame sensor malfunctions. If it isn't detecting the presence of the flame on the burner, it could shut the system down even though it's running fine. You can try cleaning the flame sensor. If that doesn't work, you may need to call a furnace repair technician to replace it for you instead.

Malfunctioning Air Pressure Switch

The air pressure switch monitors the airflow through the draft inducer motor. Since proper air pressure is essential for the ignition process, when this switch doesn't detect sufficient air pressure, it can shut down your furnace system. 

Sometimes the pressure switch malfunctions. If it gets stuck, it can cause your furnace to shut down shortly after it fires up. This can be harder for you to detect, so you may need to have a furnace repair technician evaluate your furnace to determine if the air pressure switch is the cause of the problem.

Failing Draft Inducer Motor

The draft inducer motor is responsible for supplying air to the furnace for the ignition process. If your draft inducer motor is failing, it may not supply enough air to trigger the air pressure switch. If this is the case, you'll find that your furnace turns on, and then it shuts off again when the air pressure switch doesn't trip like it's supposed to. You'll need to have a technician determine the source of the problem with the motor, whether it simply needs service or if it needs to be replaced entirely.

Talk with a local furnace repair service technician today if your furnace is only running intermittently. He or she can check these as well as a few other common causes of furnace trouble to get your system running the way that it should be.