Should I Let My Furnace Running Constantly?

A furnace is also referred to as a heater and it is used for heating a building. Generally, it warms the air and distributes it throughout the house or a building. When we have a furnace, the first thing that comes to our mind is, is it bad for the furnace to run constantly? Keep reading to understand whether you should let the furnace run constantly or not.

Should I Run the Furnace Fan Continuously?

Whether you should run the furnace continuously or not depends on you. If you are a person who is living in a cold environment and cannot bear the cold weather, you can let the furnace run continuously. Meanwhile, if the weather is not that cold, you can stop the furnace.

In addition to it, there are few cases when running the furnace fan continuously can prove to be a wrong idea. For instance, if you have ductwork in the attic or if the ductwork is leaky then running the fan continuously will be a bad idea. After all, in such cases, if you let the fan run without stopping, it will damage the system.

It is, however, quite important to note that when the furnace fan runs continuously, it has some benefits and some drawbacks.

Benefits of Furnaces that Always On

Better Circulation of Air

The main benefit of continuously running the furnace fan is that you have a better circulation of cooled or heated air. For instance, homeowners who have multi-story homes or large houses, they will benefit from it more than homeowners with single-story houses.

It is quite important to note that since heat increases, the upper level of your home will get warmer while the lower level will remain cooler. When the fan runs continuously, it will provide you with an even temperature throughout the house. When you put the thermostat to fan mode, it will provide you with even temperatures by pulling hot air back down to the ground level while pushing some of the cooler air to upper floors through the ductwork.

Even Temperature Throughout the House

If your home is a single-story house, you can still benefit when the furnace fan runs continuously in summer months because it will even out the temperature and will prevent you from having noticeable cold spots or hot spots. There are moments when we feel that a particular area in the house is quite cold while the other areas are warm and in summer, it does not feel that great. In such situations, you can rely on your furnace to provide you with an even temperature in the house. It means when the furnace fan runs continuously, you will not feel that some specific areas feel colder than others.

Improved Quality of Air

Another important benefit of having the furnace fan run continuously is that it allows you to improve the quality of air in the house. If you have allergies or asthma, or if you have a family member with allergies or asthma, having the fan operate all the time can prove to be quite beneficial. For instance, when the fan will run without stopping, it will continue to circulate the air and will improve the quality of air.

It means that for people with different types of respiratory illnesses, letting the fan run continuously can prove to be quite beneficial.

Drawbacks of Furnace Work Constantly

Higher Electricity Bills

When it comes to letting the furnace work constantly, the main drawback is that your electricity bills might slightly increase. It is understandable that if you let the furnace run all the time, it will consume more electricity and it will naturally cause the electricity bills to increase a little. However, this is not the case with a furnace that has a high-efficiency motor. When you have a furnace with a high-efficiency motor, it will not only help you to maintain your electricity bills but it will also help you save costs. For instance, it will eliminate the need of running an air conditioner or heater because the temperature will stay even in the house.

Frequent Maintenance

Another drawback of having the furnace work constantly is that you will need to maintain it frequently. It is quite obvious that if you are relying on the furnace significantly and you are using it constantly without stopping it, you will have to consider its maintenance more frequently than usual.

If the Furnace Works Continuously, Will it Break Sooner?

When you have a furnace, you might wonder if it will break sooner if you use it continuously. The answer is no. It will not break sooner if you continue to use it without stopping even for a little time. The reason is furnace systems are created in such a manner that they can run continuously while delivering the desired results.

However, it is quite important to note that your system will only deliver the required results and will not break sooner if it is installed in the right manner with the right tools. If the system is not even installed properly, it will not meet your expectations and it will not provide you with the results that you need or expect.


Overall, it can be said that you can run your furnace continuously without worrying about whether it will break or not. Running a furnace constantly can offer improved quality of air, even temperature, and better air circulation. However, it can slightly raise the frequency of maintenance and electricity bills. You can overcome these drawbacks by using high-efficiency furnace systems. They can help you not only lower the electricity bills but also obtain the results that you need efficiently.

Contact Smile HVAC

If you are thinking about installing a high-efficiency furnace or maintaining your current one, you can contact us. At Smile HVAC, we have the expertise in the installation, furnace repair, and maintenance of furnace systems. You can rely on us for delivering optimal and very fast results.