The last thing you want in winter is to wake up in the middle of the night because it’s cold inside. Most homes have furnaces as heating systems, so most of you relate to this scenario, especially if your furnace is a few years old.
What about when your furnace runs continuously even after reaching the desired temperature? Unfortunately, such a problem can happen to furnaces and needs addressing immediately. Some furnaces will malfunction and run continuously without reaching the set temperature, whereas others will operate even after achieving the desired temperature. Either way, having a constantly running furnace is not a problem to postpone fixing.
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Is it bad for a furnace to run all the time?
The high energy bill is probably the most unpleasant effect of a continuously running furnace. Let’s not forget the discomfort from the furnace running continuously, whether the house is too cold or too hot. Of course, it’s fine for your furnace to run continuously when you live in a cool region and don’t handle a chilly environment.
Like any other machine, it’s not good for your furnace to run all the time. Its parts will wear out sooner than expected and the furnace will overheat. If it doesn’t turn off automatically (as it should when it overheats), it can risk severe damage to the motor and other essential parts. All in all, you should perform some detective work if your furnace operates continuously.
Why does the furnace operate without stopping?
Let’s see the possible reasons why your furnace might run continuously without even reaching the desired temperature:
Something is wrong with the thermostat setting
Sometimes, the most common cause is the wrong setting on the thermostat. Please look at the thermostat; set it to an adequate temperature. The U.S. Department of Energy recommendation is 68F degrees in the winter for the healthiest balance of efficiency and comfort. When you set the furnace to 85F degrees, the furnace will run for a long time to achieve the set temperature.
Check out the air filter
When the furnace air filter is clogged, it will decrease the airflow through the heating system. As a result, warm air won’t get inside your house and the furnace will run continuously in an attempt to achieve the desired temperature. You should inspect the air filter at least once a month in the winter and replace it whenever necessary.
Take a look at the ductwork
The constant flow of cool and hot air will travel through the ductwork and loosen the joints and seals after some time. The warm air will escape and the furnace won’t be able to get the air inside to the desired temperature, running continuously. Minor leaks can also develop within the ducts where you cannot see.
It only takes 15-20% of the heated air generated by the furnace not to get inside the house to make the furnace run continuously. Sometimes, duct joints need resealing, and you can tape the voids in the ductwork to fix the leaks. However, assistance from professionals will be necessary if the ducts need sealing.
There are air leaks
One reason the furnace cannot achieve the set temperature is the air leaks inside. The heated air may escape through these leaks and cause the furnace’s continuous operation. You should seal the windows with weatherized plastic, install door sweeps on the exterior doors and replace old caulking. Make sure you weatherstrip as many of the draft sources as you can.
What if the furnace runs continuously after reaching the set temperature?
Some other problems could make the furnace run constantly even after reaching the desired temperature:
The blower motor is defective
The furnace is a heating system consisting of many parts, such as the burner and the blower motor. If the burner heats the air, the blower motor will push it through the ducts inside the house. You have to check if the blower runs on its own or in accordance with the furnace. Check out the air coming from the vents—the furnace and the blower operate when the air is warm; however, if the air is cold, then only the blower operates.
Should this happen, you have to take a look at the thermostat. Is it set to “On,” or is it set to “Auto”? You should set the thermostat to “Auto”; switch it accordingly and observe if the problem persists.
The thermostat is faulty
If switching the thermostat from On to Auto didn’t eliminate the problem, you need to troubleshoot the thermostat. Maybe some of its wires are disconnected or frayed; sometimes, a simple thing like worn batteries could be the problem. Replace the old batteries with new ones and see if the thermostat starts performing as it should. If it still acts erratically, you must install a new thermostat.
