Things That Cause Your Furnace To Have A Long Run Cycle Or Not Shut Down At All
If you suddenly notice your furnace has been running all day, you may want to check the filter to make sure it isn't dusty. Also, check the fan and temperature settings on your thermostat. If you can't find any reasons why your furnace won't shut off, call a residential furnace repair service. A furnace that runs constantly drives up your power bill and puts strain on the equipment. Here are a few possible causes for this problem.
There's A Leak In The Ducts
If you've had a problem with squirrels, rats, or raccoons in your attic recently, check your ducts. The pests may have ripped open a flexible duct or pried a seam apart in a metal duct. If so, the heated air from your furnace is escaping in your attic, and your home won't heat up very well. If your home doesn't meet the temperature setting on the thermostat, the furnace may just keep running all or most of the time.
There Are Loose Wires
Loose or bad wiring is difficult to detect since most of the wiring is hidden. You'll need a furnace repair service to check the wiring and tighten or replace it if necessary. If thermostat wiring is loose, the thermostat may not trigger the furnace to shut down even when the set temperature is reached. Loose or bad wiring can also affect the blower and control board of the furnace and cause the equipment to malfunction.
The Fan Limit Switch Is Bad
The fan limit switch tells the furnace when to turn the blower off. It does this after receiving a signal from the thermostat that the set temperature has been reached. If the limit switch fails, there is nothing to signal the furnace blower to shut off, so the blower keeps running.
A furnace repair professional can check the switch and replace it. Replacing the switch is a fairly quick repair that puts an end to energy waste and equipment strain when the furnace won't shut down.
The Airflow Is Restricted
Restricted airflow causes a number of problems with your furnace. If the airflow is low, your home takes longer to heat up, and that means your furnace has to run a long time. In addition to a clogged filter, a dirty blower and furnace can restrict airflow.
The furnace repair technician solves this problem by cleaning the blower area thoroughly so air can circulate freely through your furnace. Once normal airflow has been restored, your furnace should operate normally again and make your home warm and comfortable without running all day.