• Share:
Water Around Furnace Means Clogged Condensate Drain

If you notice water around the furnace, the condensate drain may be clogged with slime. Fix the problem with chemical tablets and a larger drain hose.

By the DIY experts of The Family Handyman Magazine

Clearing a clogged condensate drain

When you see water puddling around the furnace with the A/C running, you have a clogged condensate drain tube. Condensation from air conditioning coils contains bacteria that can form slime and clog the condensate pan drain tube. You can prevent slime and eliminate drain tube clogs in two easy steps. First, remove the drain tube and fitting from your A/C condensate pan. Toss them. Next, buy a package of slime preventing tablets (one choice is AC-Safe Air Conditioner Pan Tablets; sold at Amazon.com). Follow the package dosing directions and insert the tablets right in the drain pan (Photo 1).

Next, buy a 3/4-in. MIPT barb fitting, a small coil of 3/4-in. I.D. vinyl tubing, and several tubing straps. Then install the larger tubing (Photo 2). The pan tabs will reduce slime formation, and the larger-diameter tubing will enable faster condensate flow. That usually eliminates clogging for good.

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.

    • Pan tablets
    • 3/4-in. MIPT barbed fitting
    • 3/4-in. I.D. vinyl tubing
    • Tubing straps
    • Small wood dowel

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.


Add Your Comment

Water Around Furnace Means Clogged Condensate Drain

Please add your comment

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

Report Abuse

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