DIY Furnace Maintenance

Winter is right around the corner! With the winter season comes colder weather and an increase in how often you use your furnace. Before the cold weather arrives and you start using your furnace on the daily, it is a good idea to perform full-fledged furnace maintenance. Luckily, furnace maintenance is something almost every homeowner can do themselves. In this post, we’ll describe, in detail, how to perform each step in thorough DIY furnace maintenance. Let’s get started!

Step 1 – Change Those Dirty Air Filters

Every furnace will have an intake air filter. These filters serve to keep dirt and debris both out of the furnace combustion chamber and out of your warm air supply. Since they’re so important, furnace filters should be changed every one to three months (depending on use). As luck would have it, changing the filter for your furnace is exceptionally easy. To replace the filter in your furnace, all you have to do is:

• Locate the Filter: The first, and most obvious, step in changing out a furnace air filter is to find it. Usually, you’ll find your filter in the return vent closest to your furnace. You may also find your furnace air filter inside the unit at the top or bottom (depending on where the blower fan is located in the furnace). Also, if you have a package HVAC system, then the air filter will most likely be attached to the return air duct. However, in package systems, air filters are sometimes housed in the unit itself.
• Remove the Filter: Once you’ve located your air filter, the next step is to remove the old one. If your filter lives in the return vent closest to your furnace, then simply remove the vent’s grill and take out the filter. For furnace filters inside the furnace itself, remove the case door (usually a couple of screws at the top and bottom of the furnace) and gently remove the filter. If you have a package system, then head up to the air handler portion and remove the appropriate door to access and remove the filter.
• Replace or Wash the Filter: After you have successfully located and removed the filter, it’s time to wash or replace it. If your filter is disposable, then recycle it and purchase a replacement in the exact same dimensions. For washable filters, run cold water over the filter until the runoff water is clear and let it dry completely before returning it to the system.

Step 2 – Kill Power to the System

Before you continue with your DIY furnace maintenance, you’ll need to shut off power to the entire system. You’re about to touch some of the high-voltage components inside the furnace itself, and the last thing you want is to get yourself electrocuted. To turn off the power to your furnace, you have a few different options.

Some furnaces have a handy switch near the unit that allows you to shut off power to the unit. You’ll generally find these switches in systems that see regular maintenance or service (often in a commercial setting). If you have one, the switch will be near the furnace itself. Switch it off, then use a voltmeter or “hot stick” to test for power going to the system before continuing.

If your furnace doesn’t have a power switch, then you’ll have to turn the power off at the breaker box itself. Head to your breaker box, find the appropriate breaker and switch it off. Once you’ve switched the breaker off, head up to the furnace and use either a voltmeter or “hot stick” to make sure you’ve actually killed power to the system. Hopefully, you have your breaker box labeled (most people don’t)!

In some cases, there will be a separate breaker next to the furnace where you can shut off the power without turning off power for an entire electrical circuit. These special breakers are generally found in commercial settings and in package HVAC systems.

Step 3 – Give the Whole Furnace a Good Dusting

Once the power to your system is completely shut off, it’s time to give the whole thing a good dusting. To dust your furnace, all you have to do is the following:

• Remove the Door(s): Before you can dust the internal components of your furnace, you have to be able to access them. To access the internal parts, remove the doors on the front of your furnace. Usually, there will be either a set of thumbscrews, a lever, or a set of regular screws that hold the door in place. Remove the screws, and then carefully remove the door. Place the door off to the side and out of your way.
• Use Compressed Air: A great way to dust the interior components of your furnace is to use compressed air. You can buy pre-canned compressed air at any hardware store, but a full-fledged air compressor does an even better job. Blow the compressed air until dust ceases to release from the furnace case.
• Wipe Everything Down: After you’ve given your furnace a good blow-out, proceed to wipe each component down with a gentle cloth. Be careful not to snag any parts accidentally and wrench them out of place. Also, make sure that you don’t accidentally knock any wires loose while you’re dusting.

Step 4 – Turn the Furnace on and Run it for at Least One Heating Cycle

After you’re done cleaning your furnace, put the case doors back on and turn the power back on to the system. Then, head over to your thermostat and turn the furnace on. Once it’s turned on, let the system run for at least an hour while continually looking and listening for any problems. If you don’t discover any issues, and your furnace has no trouble heating your home, then you’re done with your DIY furnace maintenance!