Generally, all forced-air furnaces have a furnace air cleaner filterthat requires replacing on a regular basis – anywhere from once a month, bi-annually, to once per year. The frequency depends on the size, type and thickness of the filter and the amount of dust and dirt it captures. Usually the thicker the furnace air filter size is, the better air cleaning it provides.

Have you recently moved from an apartment or you are a first time homeowner? If yes, you might not be aware of the importance of maintaining your furnace and its air cleaner filter, nor how to do it.

No worries, it’s simple and you have two ways of having your air filter replaced.


Option #1: Book a furnace maintenance service with CASATI

You can book a furnace maintenance service with CASATI Heating & Air Conditioning and we will take care of it for you.

When our technician visits your home and performs a regular furnace maintenance on your furnace, the old filter is automatically inspected and replaced with a new one if necessary. This is included in your service.

Woman replacing furnace filter

Air cleaner filter replacement included when you book your furnace maintenance service with CASATI

Benefits of changing your furnace air filter on a regular basis:

  • Removes pollutants from the air in your home
  • Supports the efficiency and longevity of your furnace
  • Helps alleviate allergy symptoms
  • Keeps your home cleaner, with less dusting required


3 hazards of dirty furnace filters

Recommended frequency of replacing furnace filters:

If the filter size is 1”, check it and change it once a month. For a furnace filter 4” or greater, check it once every 6 months and if it is full of dust and dirt, replace it with a new one. Generally, filters 4” or greater can last you up to a year before requiring replacement.


Option #2: You can DIY

For anybody who loves DIY projects, following are simple steps that you can easily take to replace an old air filter:

1  Find your filter

If you’re unsure of what filter to buy, go to your furnace filter cabinet and check what filter it currently uses. First, turn off the furnace and then remove the existing filter (located inside the return air vent or inside the furnace).

Read the label on the filter’s cardboard frame to determine the filter size (and in some cases, the brand).

2  Buy your filter

You can purchase furnace filters at your nearest home hardware store or from some HVAC contractors. CASATI Heating & Air Conditioning has several common air filters in stock for sale to its valued customers.

To order your air cleaner filters, call CASATI 905-460-4023and ask about our volume discount offering (advise promo code: Comfort10 and receive an additional 10% off the price before applicable taxes*).

3  Install the new air cleaner filter

  • Go to your furnace and turn it off
  • Remove the old filter by pulling it out of the furnace cabinet
  • Look for the indicator (i.e. arrow, marker) on the new filter that shows the airflow direction and tells you which side of the filter faces the furnace
  • Slide the new filter into position (a word of caution: to prevent blockage to the air flow to your furnace, ensure that the air filter is put in the furnace cabinet properly and not backwards)
  • Put back the cover or door to close the filter into place


4  Record the filter replacement date for future reference

CASATI’s technicians record the filter replacement date for you when completing the maintenance service on your furnace.

However, if you are replacing the furnace filter yourself, then it is recommended that you record the date you put in the new filter so that you know when your filter is next due for inspection and/or replacement.

Written by Nicole Casati

Do you have your own tips to share with us? CASATI HVAC would love to hear from you and learn more about new, innovative ways to create the perfect home experience.