How Often Should You Have Your Furnace Cleaned?

May 04, 2023


To get the most from your furnace, you should get it cleaned and maintained at least once a year. We get how challenging this can be. After all, your furnace is hidden away out of sight in the back corner of your home. 

But the truth is, your furnace keeps you warm and comfortable, and when it starts to get chilly, you want to make sure it’s in top shape. In Utah furnaces run for thousands of hours every year. If you have central air conditioning your furnace runs all year long to circulate the air whether you’re heating or cooling. That’s a lot of wear and tear on an appliance that can seem out of sight and out of mind.

Benefits of Having Your Furnace Cleaned

Cleaning your furnace does more than help your home and your health. A clean furnace will:

  • Run more efficiently – A dirty furnace will have dirt covering the blower motor, switches, heat exchanger, and even the ignition. If there is dirt or grime covering these parts of the furnace, it will have to run longer cycles and work harder to provide the same amount of heat.
  • Last longer – Furnaces are built to last, but dirty parts speed the aging process for the electronic elements like the switches and controls, and can even cause premature aging in the blower motor, fan, and heat exchanger.
  • Run safely – A dirty heat exchanger may crack prematurely and can emit carbon monoxide in your home’s air if it’s not repaired.

How to Clean Your Furnace

If you plan on cleaning your furnace, you first need to determine if you have a gas or electric furnace. Depending on the make and model of your furnace, the way you clean it can vary. Make sure to also double-check the manufacturer’s information before cleaning. Some models should only be cleaned by certified professionals.

Cleaning an Electric Furnace

If you’re looking to know how to clean your furnace, you need to make sure you have the tools you’ll use to clean and maintain it:

  • Replacement furnace filter
  • Damp rag
  • Vacuum cleaner
  • Phillips-head screwdriver
  • Flathead screwdriver
  • Stiff toothbrush

Once you have your equipment together, follow these six steps to clean your electric furnace:

1.     Turn the electricity to the furnace off.

Always turn the power to the furnace off before attempting any service or maintenance. There will be a switch that looks like a light switch near the furnace. The switch will be mounted on the wall near the furnace or even on the furnace. Flip the switch off to disconnect the power to the furnace. If you are unable to find the switch, go to your home breaker box and turn off the electricity to your furnace through the corresponding circuit breaker.

2.     Replace the filter.

To start your furnace cleaning, lift the blower access panel door up and away from the furnace. You should be able to see the filter. You won’t be able to see both sides of it, so remove and inspect it. Replace the dirty filter with a fresh one. You can replace your filters as often as once a month depending on the amount of use and the air conditions in your home.

3.     Vacuum the inside of the furnace.

Using attachments on your vacuum, remove any visible dirt, debris, or dust from the inside of your furnace. You should focus especially around the blower wheel. If there is any tough dirt that will not come up when you vacuum it, you can use a stiff toothbrush to scrub the dust off and clean it up with a damp rag. When using a damp rag, make sure that it is only minimally damp as you do not want to leave behind any excess moisture in the system as water can cause rust and corrosion. Be cautious around any wires while vacuuming. Make sure to avoid damaging or disturbing them in any way.

4.     Inspect the wires and belts.

Look at the wires around the blower wheel and the coils. You can tighten any loose terminals with a Phillips-head screwdriver. Check the belt that operates the blower for frays or damage. If there is any damage to the belt, or if you feel like the wires need to be replaced, contact a qualified HVAC technician to make sure they are replaced properly.

5.     Clean all heat registers.

Locate all of the heat registers around your home, and using a flathead screwdriver, remove the register grill from the wall or floor. Carefully insert a vacuum hose into the duct and remove any dirt, dust, or build-up you can. Never push or shove your vacuum hose into a duct, to avoid damaging the duct in any way.

6.     Clean up and turn the power on.

Set all removed grates, panels, and registers back into place and secure with screws where necessary. Double-check all panels to make sure they are cleaned and secure. Make sure you have all the tools you used as part of your cleaning. You do not want to leave a screwdriver in your furnace when you turn it on. Once you are sure all tools have been safely removed, and the furnace system has been closed up correctly, turn the electricity to the system back on.

Cleaning a Gas Furnace

If you are using a gas furnace and want to know how to clean a furnace, cleaning it will be similar to maintaining an electrical furnace, but it will require a few additional steps. Before you start cleaning, make sure you have the following tools:

  • Replacement furnace filter
  • Damp rag
  • Vacuum cleaner
  • Phillips-head screwdriver
  • Flathead screwdriver
  • Stiff toothbrush
  • Ratchet and socket set
  • Emery cloth

Once you have your equipment together, follow these 10 steps to clean your gas furnace.

1.     Turn off the power and gas to the furnace.

While your furnace uses gas to create heat, there are still electrical elements as part of it.  So you need to make sure you turn off both the gas and electricity to the system. To turn off the electricity, there will be a red switch that looks like a light switch, near the furnace. The switch will be mounted on the wall near the furnace or even on the furnace. Flip the switch off to disconnect the power. If you are unable to find the switch, go to your home breaker box and turn off the electricity through the corresponding circuit breaker. To turn off the gas, give the gas valve a 90-degree turn. If your furnace was in use before you started maintenance, make sure to give it some time to cool off.

2.     Clean the furnace.

Remove the furnace access door by lifting it up and out. Loosen any screws and remove the burner cover, if there is one. Using your vacuum, remove any dust from the burners and furnace base. Don’t forget to lift the blower door and vacuum the compartment. While you are vacuuming, look for signs of soot, which indicates poor combustion and a need for further maintenance.

3.     Remove the blower.

There might be a control panel that blocks the blower, if there is, unscrew the control panel and let it hang. Using a socket and ratchet, remove the bolts that hold the blower and gently remove it.

4.     Carefully clean the blower.

The blower is balanced, so it is important to clean it carefully. Make sure to clean it with a vacuum and small brush without disturbing the wiring and counterweights on the fan blades.

5.     Clean the flame sensor.

Pull the flame sensor down and out of its bracket. Using a fine emery cloth, clean it, and slide it back in. If the sensor is dirty, it can prevent your furnace from lighting.

6.     Inspect the drive belt.

Check the blower belt for any cracks or fraying. If there is any visible damage to the belt, contact an HVAC professional to have it replaced.

7.     Replace the air filter.

Remove your existing filter, and replace it with a new filter. Don’t upgrade to a higher-efficiency filter without checking manufacturer recommendations. Some gas furnaces are not able to use these filters, and they can cause strain on the blower motor and reduce your furnace’s efficiency.

8.     Close up the furnace.

Put back any system you removed including the blower, control panel, and access door. 

9.     Activate the system.

Turn the power and gas back on. Depending on the age of your system, you might have to light your pilot light. Check that burner flames are even and blue. Yellow flames indicate dirty burners. Cleaning and adjusting burners is a very sensitive job, and it is NOT recommended as a DIY project; they are sensitive and can easily break if handled improperly. Contact an HVAC professional for maintenance on your burners.

10. Adjust dampers.

If your heating ducts also serve as AC ducts, adjust the dampers for seasonal settings.

Trust a Professional

When you’re looking for a faster, easier way to accomplish seasonal furnace maintenance, trust a trained professional from Yes!. Our team is ready to give you a furnace repair that lasts. If you’re fed up with your old furnace and looking for installation and replacement, we can handle that as well. With a wide variety of payment options available, we make sure that you can afford to replace a furnace or air conditioner when you need to. Contact us today to get help with all of your heating, cooling, and plumbing needs.

Last Updated: February 22, 2024