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How to Change Your Furnace Filter

The furnace filter plays a critical role in your furnace’s operation, but it is often overlooked because it looks like such a small and insignificant component. It filters out dirt, dust, hair, and other allergens when air passes through the furnace. Without this filter, the furnace would get all those particles stuck inside the unit and it would most certainly affect usability and lead to issues with the internal parts. While the process of filtering the air is designed for functionality, as a bonus, you get to breathe cleaner air. Knowing how to change your furnace filter is an important part of home ownership. It is a general rule that you should change your furnace filter approximately every three months. This is dependent on various factors such as, how thick your filter is, the size of your home, and how many pets you have in your home. Thicker filters can go longer in between being changed. However, bigger houses and houses that have multiple pets, need filters changed more often. But every three months is a good starting point. Fall is a great time to think about it in Ontario, as you should change your filter before starting your unit up for the first time when the cold weather sets in.

Locating the Filter

Before you can learn how to change your furnace filter, you first need to locate it. There are several places where a furnace can house a filter. This will depend on the manufacturer and the way it has been installed. On most furnaces, you will be able to find the filter in between the return air duct and the blower compartment. The blower compartment is the lower section of the furnace located below the heat exchanger compartment. The return air duct connects directly to this lower blower section. If you have any trouble locating it you can refer to your owner’s manual.

How to change your furnace filter

Type of Furnace Filters

Now that we know how often to change it and where to find it, let’s talk about determining what filters to buy. The furnace filter’s efficiency at filtering out particles is measured by a MERV rating; this rating can tell you how effective it is and how much dirt and allergens it will filter out. Filters start with a MERV rating of 1 and go all the way up to 20. For example, if you have a MERV rating of one, this means the filter is going to be very thin and should be replaced more often. On the flip side, if you have a MERV rating of 13, it will be quite thick and can last longer. It is important to read your manual to see what filter size is recommended, in some cases, a filter can be too thick and make the furnace work too hard. You want to have the best filter for your equipment to allow it to still work properly and not cause any damage. MERV ratings for residential furnaces typically range anywhere between 7 and 13. Some of the higher rated filters require a special attachment on your furnace in order to be used to accommodate their larger size or in some cases electrical power requirements. If unsure, talk with your trusted heating expert to make sure the filter size you want will fit. When you pull the filter out it will have measurements on the side, this will tell you what has been in there previously and if you would like the same type, what size you need to buy to replace it (remember, as long as the size is the same, you can replace with a higher MERV version if you desire. In other words, you do not need to replace like-for-like).

Changing the Filter

After you have located the filter and made sure you have bought the right one, it is time learn how to change your furnace filter. The most important part is to make sure the furnace is off. Open the door on the filter housing and slide the filter out. If you look at the old filter you will see how dirty it is, this shows you why you need to replace it. Throw away the old filter and put in the new one making sure to position it in the proper orientation of the air flow (remember, the direction of air flow will be indicated on the filter itself and the air to your furnace flows from the return air duct towards the furnace). Close the door back up where the filter went in. Now you can turn your furnace back on. If you are unsure of how often you need to change your filter, check back in about a month, and see how dirty the filter has gotten. If you see that it is very clogged up then you know that you need to change it after about a month.

Now you know how to change your furnace filter. It is a simple job but a surprising amount of people do not know how to do it. Knowing how to change your furnace filter yourself saves you having to pay a technician to do it. However, getting an annual maintenance on your heating system is important and the filter change can be done by a technician at this time. You can save a little bit of money by doing it yourself, but paying your heating expert to take care of it is a minimal amount and takes one thing off your plate. Your heating experts at Doyle Home Services are always here to help, call to book an appointment to get your annual maintenance done on your equipment now.

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