Why is ice building up on my furnace exhaust?
Heavy ice builds up outside on furnace exhaust pipes during winter, forcing homeowners to go out and knock it down every three to four days. It leaves people wondering whether this constant freezing is a normal amount of ice accumulation.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
- 1knocking down the ice every 3-4 days
- 2kicking the ice over from time to time
- 3Soaking up accumulated water manually
- 4Using a semi-flexible wire to push through the holes
- 5Blowing air through the holes using an air line, canned dust cleaner, or air compressor
- 6Sucking out debris using a wet vac with a modified small nozzle, straws, or duct tape
- 7Using interdental brushes or pipe cleaners
- 8Pouring boiling water, Drano, baking soda, or vinegar down the channel
- 9Making new drain holes leading outside
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“Every year I have to soak up water that accumulates into my sliding door rail because the weeping holes don’t seem to do their job.”source ↗
“I have tried sticking a small semi flexible wire (meant for hanging pictures frames on the wall) and have inserted as much as 20 inches of it and haven’t had any luck with dirt or water starting to poke out from both holes.”source ↗