Why You Should Clean Your Furnace Blower (If it’s Dirty)

furnace blower illustration

Neglecting to keep your furnace blower clean (along with your air ducts), is always going to result in one of three bad options:

  1. Expensive furnace repairs
  2. Having to replace your furnace
  3. Wasting money on higher energy bills

Dirty Furnace Blowers Cause Expensive Repairs

furnace blower motor cost

When the blower wheel in your furnace becomes coated with dust, it forces the motor that powers it (the blower motor) to work harder in order to keep the wheel spinning at the proper speed. This additional strain on the blower motor causes it to draw more amperage (use more energy) than normal, and will result in the blower motor burning out.

If you’ve ever had to replace the blower motor in your furnace, you know it’s expensive. While the cost varies in different parts of the country, it will cost you at least $1,000 to have any of the well-known, reputable furnace repair companies in Denver replace your blower motor. Not only will you have to replace the blower motor, but in order for the furnace repair company to warranty the new blower motor, you’ll also have to have the dirty blower wheel cleaned as well.

So no matter what, you’re going to have to have the blower wheel in your furnace cleaned at some point. It just down to whether you procrastinate long enough to cause an expensive furnace repair to go along with the cleaning.

Dirty Furnace Blower & Cracked Heat Exchangers

cracked heat exchanger

The cycle of working harder to push less air through your HVAC system also causes the heat exchanger in your furnace to operate at a higher temperature than it should. You may have heard the term ‘cracked heat exchanger’ before, and it means you’re going to have to replace your furnace, no matter how old it is.

When tiny cracks start to form in the heat exchanger in your furnace, carbon monoxide can begin to leak out into your home. These carbon monoxide leaks usually start out as small leaks, but can quickly become larger, more dangerous leaks as your heat exchanger continues to heat up and cool down as you run your furnace. Carbon monoxide leaks, as you probably know, can be deadly. Having one of the well-known, reputable HVAC companies here in Denver replace your furnace will cost anywhere from $4,000 to as much as $10,000, depending on the type of furnace you have and the company you choose. So it’s worth the relatively small investment to keep the furnace clean so the heat exchanger doesn’t fail, forcing you to replace it sooner than you should.

*If you don’t have a working CO Detector in your home, be sure to get one asap.

Dirty Furnace Blowers Cause Higher Utility Bills

utility bill illustration

If you ask an engineer from one of the major furnace manufacturers, they will tell you that as little as 1/10th of an inch of dust can reduce the efficiency of your furnace by as much as 20%. If you look at a tape measure you’ll see just how thin a coating that’s only 1/10th of an inch would be. If you don’t have a tape measure handy, take my word for it, it’s not much.

When dust and dirt build up on the blower wheel, your furnace has to work much harder to get the warm air where it needs to go inside your house. Most people are surprised to learn that the furnace blower is also what pushes the cold air over your evaporative coil, and then through your ductwork in the summer when you air conditioner is running. So even a tiny buildup of dust on the furnace blower wheel can increase your utility bills significantly not just in the winter, but also in the summer.

If you think about how much you spend on utility bills over the course of an entire year, imagine adding 20% on top of that simply for neglecting to have your dirty furnace blower wheel cleaned.

When your blower wheel is dirty, the blower motor has to work harder, which means it draws more amperage (energy) in order to try and spin the blower wheel at the speed it needs to turn. At the same time your system is working harder, the blower wheel isn’t able to push the same volume of air as it normally would. So you’re spending more money, and getting less efficiency and performance from your HVAC system.


None of the three options that result from neglecting a dirty furnace blower are good. It’s a simple issue to take care of, especially if you are already considering investing in professional air duct cleaning service. The technicians are already there at your house, and you can save a significant amount of money when you have the furnace cleaned at the same time as your air ducts. Just as air duct cleaning is a smart investment in your health and home, including a furnace blower cleaning will save you money and help you avoid expensive headaches.

Still Have Questions?

Ready To Schedule Your Duct Cleaning?

Call Us At 303-995-0627

Want More Information?