Why Won’t My Furnace Shut Off in Stafford, VA?

Standard furnaces typically run a few heating cycles per hour. It can cause concern when you realize yours is running constantly as it usually signals a problem. Consider the following common reasons your furnace in Stafford, VA, might not be shutting off and what you can do about it:

Thermostat Fan Setting

Start by checking the fan setting on your thermostat, which should remain set to “Auto.” When it’s set to “On,” it’ll continue running whether or not the system is in a heating cycle. In this case, it appears the furnace is running, but it’s just the circulating fan.

Old or Faulty Thermostat

Your furnace may continuously run if your thermostat isn’t accurately registering the temperature in your home. While this can happen at any age, it’s more common toward the end of the thermostat’s expected service life. Many usually have a lifespan that’s upward of 10 years.

Issues With the Blower Motor

You could have an issue with your blower motor if your furnace is running but not producing heat. Common problems include issues with the fuse or electrical wiring for the motor that controls the circulating fan. Your service technician will check the condition of these connections during your annual furnace maintenance appointment.

Faulty Upper Limit Switch

The upper limit switch monitors the temperature of the system and shuts it down if it overheats. It’s also where the thermostat sends the signal to cycle on and off. A faulty switch may not send the right signals to the furnace, causing it to continue running.

You Have a High-Efficiency System

Some high-efficiency systems have modulating burners and variable-speed fans. These components allow the furnace to run at a lower capacity but will run almost constantly. Check with your service technician during your next repair or maintenance visit to see what kind of system you have.

Don’t let your utility bills skyrocket while your furnace runs constantly. Schedule a furnace repair appointment with one of the service technicians at Brennan’s Heating & Air Conditioning. You can reach us 24 hours a day, every day of the week.

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