Frozen Waste Pipe – how to fix it

By Andy the stuff doer

It certainly is a cold snap we’re having at the moment, this morning the kitchen sink would not drain.  This freezing problem could happen to bath drain pipes, basin waste pipes, shower waste pipes, washing machine drain pipes and in extreme circumstances toilet soil pipes and stacks.

This trick also works for condensate drain pipes from combi boilers, white or grey 20mm plastic pipe that comes through the wall behind the boiler and leads to a drain.

The freezing occurs where the pipe is outside as it runs to the soil stack or drain.

frozen sink waste pipe

Sink/ bath/ basin waste pipe where it enters the soil stack

It took some thinking about to come up with a quick fix, this is it

Wrap some towels around the pipe, the thicker, most layers the better. Then pour very hot water water over the towels so they are soaked.  BE CAREFUL OF SPLASHES AND SPILLS.

fixing, ublocking a froozen waste, drain pipe

Pipe wrapped in towels with hot water pored over

When the towels have cooled, apply another soaking.  This was enough to open up our 32mm waste pipe so the sink drained.

Then run hot water from the tap for 10 mins to melt out any ice that’s left.

As a preventative measure I could now lag the pipe but I think the most important thing will be to make sure that no  taps are dripping.

DONT turn your computer of just yet. Try the solution and let me know how you get on. (Comments and Replies below)

Let everyone know. Please feel free to drop a link to this article via facebook, twitter etc.

And thanks to The Cheaterfield Post for suggesting I add this to my blog.

31 Responses to “Frozen Waste Pipe – how to fix it”

  1. I hope this solution solves your frozen waste pipe problem. Please leave a comment to let me know if it’s worked for you.

  2. jack frost belfast on December 21st, 2010 at 11:57 am

    thanks for this- bath didnt drain this morning- wrapped the waste pipe with towels as above- result!!!

  3. This worked when all else failed. Our bath didn’t drain and we tried everything – even anti-freeze as recommended by a plumber. We tried your method and it cleared in minutes. Thanks

  4. Does this technique also work on toilet waste pipes? Also, any ideas how I can get the towel round the pipe when I’m in a 2nd floor flat??


  5. Yes it will work on toilet waste pipes but you do need safe access to it. eg. a ladder.
    Alternatively it’s a good exercise in problem solving. String, a long stick and a hose pipe might be required.

  6. Well, it worked for me!! The drain from the sink froze outside, and the dishwasher flooded. Have wrapped towels and applied hot water as instructed and hey presto!! Many thanks. Teenage children especially grateful as dishwasher may be fixed soon, so they only have to load it, not wash up…..

  7. Worked really well.

  8. My Shower cubical is blocked from the plug hole/tray entrance right the way down will this method work? I tried last night tipping boiling hot water down the plug hole to loose it, to no avail Any other solution you could come up with. Best Regards Siobhan

  9. This really works!! Sink downstairs would not drain for nearly two days. Followed instructions to the letter and it ran free in minutes. Thank you.

  10. Siobban, If there’s no flow at all then tipping hot water down wont get down to the ice. If the shower drain is iced up right to plug hole then you shower room is below freezing and you need to get some heat in the room. Are you sure it’s not just water backing up from the blockage?

    Try the technique on the outside pipe. As soon as you get any sort of flow then you can start pouring hot water down the plug hole.

  11. Another method I have just used. Syphon as much water out of your system as posible. Then pour in boiling water. Object is to get boiling water as near to the ice as posible. Just done this with my upstairs wash basin. Had to repeat process but it then cleared within a couple of minutes. When clear run plenty of hot water through your system to make sure all ice is removed.
    Good luck

  12. Thanks for this tip. I’d tried everything to unblock the waste pipe from my washing machine but this was the only thing that worked.

  13. Good one David, Syphoning could be the trick to use when the outside pipes are inaccessable. It is more hassel as you have to disconect the trap or u bend to get the syphon tube down to the blockage.
    And be careful sucking on the tube, I wouldn’t fancy trying it on a toilet but it could work for ‘Cat’s problem’

  14. I have to admit i was dubious, but this worked first time. Brilliant!

  15. Worked for me this morning. Many thanks! Saved me getting a plumber out. Just wrapped the pipe in towels (it was a long run), like you said, poured boiling water over, reboiled kettle and repeated. Success. Can’t thank you enough.

  16. Thanks this worked for me , i had water backing up in my kitchen sink.
    I did what you said and the water flows free now.

  17. Wow did this without towels and no success. Then read this with towels and wow bingo. Thanks and merry Xmas to everyone.

  18. Thanks to everyone whose has commented (more always welcome). It’s great to hear that this tip has worked well for so many.
    A Merry Christmas to you all.

  19. You are a genius! Worked 1st time. Thought i would be waiting for hours being xmas day and there you go.
    Thank you. Much appreciated,all the best.

  20. You must have really mild winters there. In the Continental U.S. there aren’t any locations that don’t get the occasional freeze that would completely destroy that plumbing. Even Florida and California get bad freezes. Plumbing has to be run inside the walls, and it’s illegal to run it in an external wall other than passing through to an outside tap. Even then we sometimes get breaks in the winters in Michigan. Just bought a big house for a little price because that happened after the last owners moved out.

  21. Thanks so much! It worked first time!
    My cloakroom was flooding as washbasin overflowing.Noticed the tap is dripping ….how do I fix that? It’s an old fashioned one.

  22. Thanks for letting me know tip for Frozen waste pipes worked for you.
    Fixing a driping tap, I’ll have to cover that when I next do one. But in brief, turn of the water, unscrew the top cover, you might have to take the handle off to remove it completely. You should see two nuts around the shaft , unscrew the big, lower one. ( it might be really stiff so a big wrench and something to hold the tap body from turning). You should then be able to see the problem, often the rubber/leather washer needs replacing or it might be the metal seat that needs smothing off (tap reseating tool required). Hope this helps.

  23. fix it…

    […]Frozen Waste Pipe – how to fix it[…]…

  24. Many thanks, even these several years later it still works fine, even at 23:45 outside, up a ladder, in -5C and falling snow, plus pitch black except for a small torch!
    (The upstairs bathroom basin waste pipe exits the house and flows, or not, into an open “basin” at the top of the down-pipe.)
    P.S. used an old T-Shirt rather than a Towel…
    P.P.S. can’t fix the dripping tap just yet, won’t turn even with the right tool (or a huge spanner)…

  25. This worked first time. My waste pipe is very close to a wall with not enough space to get a towel around the pipe so I cut an old cardigan into strips and pushed them through the narrow gap with a screwdriver to wrap the pieces round. When done, just one soaking with hot water was enough to unblock the pipe within a couple of minutes. Great advice. Thank you.

  26. It’s good to know it’s still good advice, there has been thousands of people with the same problem over the last couple of days (judging by the views of this post). Thanks for letting me know it worked for you.

  27. Cheers John, Sounds like quite an adventure you had. It might be time for a new tap although it is usually possible to take old taps apart with tenacity and maybe some heat.

  28. Thank you so much! The Beast from the East left me with a kitchen sink half-full of dirty dishwater for 2 days ?. 3 tea towels and 2 kettles of hot water later and it’s all sorted! Brilliant! ?

  29. I’ve been struggling for the last couple of hours with just boiling water and not getting anywhere so now going out to try it with towels… thanks ?

  30. Success in minutes….. this worked so quickly

  31. Hey thanks for this. Thought it was a build up of hair but realised it had been extra cold last night. Fixed the problem in minutes. I’ll look into getting these pipes lagged properly to hopefully stop it happening again. Cheers m8.

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