After your Boulder, MT, home’s furnace shuts off, it’s normal for the blower fan to run for a few minutes to distribute the heat and cool down the internal system. If you’ve noticed that the fan continues to run, there are several possible reasons why it refuses to shut off.
Thermostat Switch Isn’t on the Right Setting
One of the most common reasons why the furnace fan continues to run is the setting on the thermostat. If someone has switched the fan setting to “on” instead of “auto,” the fan will run constantly.
Thermostat or Its Wiring Is Faulty
Another possible issue that has to do with the thermostat is that it’s faulty. The thermostat’s wiring may be damaged.
When you suspect the problem with the fan is the thermostat, have it checked out. A repair professional may need to replace the thermostat or change the wiring. You can prevent problems in the future by having your thermostat and its wiring checked during each scheduled preventive maintenance visit.
Fan’s Limit Switch Isn’t Set in the Right Mode
After ruling out problems with the thermostat, another possible reason the furnace’s fan refuses to shut off is the limit switch. If you or someone else has set the limit switch to manual mode, it won’t automatically regulate the temperatures until it’s set to auto mode.
After finding the switch on the outside of the furnace, check to make sure it’s set in the proper mode. If the limit switch is in the right mode and the fan is still running, the switch may be malfunctioning.
If you can’t shut off the furnace’s fan with the simple flip of a switch, there may be an underlying issue with the furnace or thermostat that needs repairing. Contact us today at Superior Heating & Cooling, Inc. to schedule a service call.
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