Save money now and later: How to change the filter in your furnace

The filter is the lifeblood of your furnace. It might look like a jumble of cardboard, felt, and wiring but it’s actually really important. Changing out your filter every three months is critical to maintain your furnace and avoid expensive repairs down the line. Repairing your furnace or worse, having to replace it, is very costly. Plus, the filter collects dust and you’re breathing in all that junk if you don’t change it. The good news is that swapping out your filter is super easy and inexpensive. It only takes a few minutes once you get the hang of it. Here’s what you need to know to become a filter-changing pro: 

How often should you replace your furnace filter? 

The general rule of thumb is every three months. More specifically, 1-2 inch filters every three months, 4 inch filters every six months and 5 inch filters every 12 months. However, it can also depend on how dusty your home is or how often you heat or cool your home. If you have some furry friends living with you, then you may want to change it more often. 

Find the right filter size.

The easiest way to figure out what size filter to buy is to look at the one that’s currently in your furnace unit. The size should also be indicated in the furnace’s manual. They come in a few standard sizes, all of which you can find at a hardware store or order online. We recommend buying a multi-pack so you always have extras on hand.

Air filters come in all sorts of fun varieties. There are some that claim to be best for allergens and others that are for pet hair. The choice is yours as long as you buy the correct size.  

Set reminders in your calendar – or opt for a smart filter.

Setting a recurring reminder in your phone’s calendar will help ensure that you don’t forget to replace your filter. If you prefer a modern solution, companies like Filtrete make smart air filters that have a sensor in them to monitor air flow and usage. It connects to their app which will alert you when it’s time to make a change.

How to replace the filter:

1. First, make sure your furnace is turned off.

2. Locate where the filter is housed. It’s usually underneath the unit. Unscrew the cover plate to get to the filter. There are typically two screws – one on either side. 

3. Before removing the old filter, check to find the direction of air-flow. You’ll see an arrow on the edge of the filter that’s pointing in a direction. That’s the direction of air-flow and it’s important to install the new filter in the same direction. Pro tip: draw an arrow with the airflow direction in permanent marker on the actual furnace housing or ductwork. Ideally, you’d indicate the airflow direction and filter size ( i.e. 16x25x4  Airflow→). 

4. Then, remove the dirty air filter by simply pulling it out.

5. Slide in the new filter in the correct direction and screw the cover plate back on. That’s it! 

Fixer is here to help you replace your air filter.

You’ve got this, but if you need any reassurance or run into trouble during the process, book a video consultation with one of our home repair pros. We’ll troubleshoot your furnace unit in real-time and provide clear instructions on what to do next.