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PRK Services, Inc. Blog

What Happens if You Don’t Change Your Furnace Filter?


This time of year, you might not be thinking about your furnace very much. But it’s actually a great time to assess how well it was working over the winter and make a plan to help keep it running as long—and as well—as possible.

In fact, if you’re honest, you probably didn’t think about your furnace a whole lot even when it was running every day. You might only think about it when it isn’t working well! 

The two things you can do to help your furnace run efficiently, require fewer repairs, and last longer are annual maintenance and changing the air filter. While the annual maintenance must be done by a professional, you should be changing the air filter every 1-3 months yourself. What happens if you don’t change your furnace filter? We’ll tell you all about it.

Dust and Grime

The air filter’s job is to collect contaminants that would otherwise infiltrate the furnace. When a filter isn’t changed, that dust and grime will try to force its way through around the filter, because the furnace will be pulling harder and harder to try to get enough airflow.

These particles will gum up the works, leading to dirty components that can’t do their job as well as they should. One of the most serious issues is causing increased friction in the moving parts such as the fan and fan motor. These components are carefully cleaned and lubricated during maintenance to make sure they glide freely, and once-a-year maintenance should be sufficient to keep them moving smoothly.

But if you don’t change your furnace filter, they’ll get dirty much faster, and that friction will lead to inefficiency and poor performance, and can even cause the motor to completely overheat and burn out.

Low Airflow

The other main concern with a dirty air filter is that it won’t allow enough air through. The furnace passes cool air over a heating element or heat exchanger, which warms the air, and it is then circulated to warm your home. But if it can’t get enough cool air, the heat will be trapped in the furnace.

The limit switch will be tripped because it will sense that the furnace is getting too hot, and the furnace will turn off. As soon as the temperature drops a bit, the furnace will try again, overheat again, trip the limit switch again, and shut down. This is called short cycling.

As you can tell, it means that the heat won’t circulate properly and warm your home. But while you’re not experiencing enough warmth, the furnace itself is experiencing too much. The rapid cycles and high temperatures will strain the system. It can cause damage to a variety of components and even shorten the life of the furnace dramatically, and in the meantime, it will be using a lot more energy than it should. This means you’ll be paying more for heat while getting less of it.

If you notice any of these issues occurring with your furnace in Flower Mound, TX, it’s no longer just time for maintenance. Your furnace will require repairs. At that time, if you’re not sure exactly how to change your air filter, or you have questions about how often to do it or what else you can do to prevent furnace problems in the future, your technician will be happy to provide all the information you need.

Contact PRK Services, Inc. today for all your cooling and comfort needs.

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