• Share:
How to Change a Furnace Filter

Check your furnace filter monthly and change it when it's dirty. You'll get better heating in the winter and air conditioning in summer. You'll save on your utility bills and extend the life of your furnace too.

By the DIY experts of The Family Handyman Magazine

  • COST
  • Cost Under $20
  • close X

    New filters cost from $1 to $10 depending upon the type of furnace and the degree of air filtration you want.

When to change a furnace filter

If you're thinking that you only have to change your filter once a year, you may well be shortening the life of your furnace. Actually, you should check your filter monthly and often change it monthly, depending on the type of filter you use. To determine if it's too dirty, remove the filter and hold it up to the light. If you can no longer clearly see light, change the filter (see photo).

Many costly repairs can be avoided with regular filter changing. If you don't change the filter, lack of airflow through the furnace will cause it to overheat and shut down. Similarly, a dirty filter can cause an air conditioner to shut down because the coils freeze up when airflow is inadequate. Both events stress the system.

Filters are designed to protect the blower motor from dirt. When buying filters for this task, an inexpensive glass fiber filter will do the job. But if you want to reduce airborne dust in your home, you could start with the best of the inexpensive 1-in. disposable filters—the standard pleated filter—which costs a bit more. Better yet, to remove even more small particles, install an inexpensive, electrostatically charged fiber filter. 3M Filtrete is one common brand.. Just make sure to check the filter monthly and change it when it's dirty (not just every three months as recommended).

All other options, from a 4-in. thick mechanical air filter to an electronic filter plate system, involve electrical or ductwork changes by heating/cooling contractors. They remove more particles, last longer and cost more.

Finally, whatever filter you use, make sure you reinstall it correctly, with the arrow on the filter edge pointing toward the blower motor. Putting it in backward decreases the filter's efficiency.

Back to Top

Required Materials for this Project

Avoid last-minute shopping trips by having all your materials ready ahead of time. Here's a list.

    • Furnace filter

Comments from DIY Community Members

No comments on the article have been posted yet. Be the first to add your comment!

You will be required to log in or create an account to post a comment.

closeX

Add Your Comment

How to Change a Furnace Filter

Please add your comment
closeX

Log in to My Account

Log in to enjoy membership benefits from The Family Handyman.

  • Forgot your password?
Don’t have an account yet?

Sign up today for FREE and become part of The Family Handyman community of DIYers.

Member benefits:

  • Get a FREE Traditional Bookcase Project Plan
  • Sign up for FREE DIY newsletters
  • Save projects to your project binder
  • Ask and answer questions in our DIY Forums
  • Share comments on DIY Projects and more!
Join Us Today
closeX

Report Abuse

Subject
Reasons for reporting post

Free OnSite Newsletter

Get timely DIY projects for your home and yard, plus a dream project for your wish list!

Follow Us

Featured Product

Buy Now