The water supply line to my toilet is frozen going on about 24 hours now. It is in the upstairs bathroom along the north wall, the only water line in the house that is frozen. All other pipes/drains/showers/toilets ect seem to be working fine, all are dripping.
The line is in the exterior wall and I am not able to get to the pipes.

Do I call a Plumber now?

I have a heater in the bathroom and the room below that bathroom Is my kitchen so I’ve turned the heat up in my house to 74 degrees hoping it will help to thaw the pipe as well just now. Had it on 69 before the pipe froze then up to 71 until an hour ago. My pipes are PEX pipe.

It is supposed to be below freezing for about 6 more days then should thaw out. Again, I’d love any suggestions and should I call a Plumber now or wait?

I’m losing sleep worrying. Any suggestions?

Thank you in advance for any and all advice.

  • If inside the wall, will probably need to open wall,where pipe is to let the heat in. A hole near bottom at least half foot(6x6). Something can recover with a small door like cover. Check often to make sure pipe not leaking, might take most of a day. Know where to shut off water if pipe is broken/leaks. Pex pipe should be a bit nicer not to crack from frozen water.
    – crip659
    Commented Feb 14, 2021 at 13:13
  • "open wall"? What are we imagining an exterior wall is made of? I actually think we really do need clarification on a lot of this. I can't imagine any scenario where pipes would be in any exterior wall, then again I can't imagine any exterior wall that can be "opened"...
    – Tetsujin
    Commented Feb 14, 2021 at 13:25
  • @Tetsujin I am hoping that the inside of exterior wall is covered with something like drywall. Something easy to take a small piece away and let heat in.
    – crip659
    Commented Feb 14, 2021 at 13:44
  • hmm. OK. I'm not used to buildings with 'drywall' on exterior walls unless it's used as a 3rd layer of thermal lining, after the 2 courses of brick & cavity insulation ;) I suppose I should have considered it would be a US-based question after temperatures were in ℉ & probably Dallas area, though a quick google says Dallas gets more freezing days than London, so you'd think building code would be prepared for it.
    – Tetsujin
    Commented Feb 14, 2021 at 13:51
  • @Tetsujin Usually houses here use 2x4/2x6 studs, outside is usually just exterior sliding(brick or something), and living area has a covering, mainly drywall with insulation inside studs.
    – crip659
    Commented Feb 14, 2021 at 14:33

1 Answer 1


Oh. I just realised "the line is in the exterior wall" - you mean buried inside a wall itself, or that it comes in from the outside? How close to it can you get? Can you see any part of it to examine it? I've never seen any building with piping buried in exterior walls (just because of this precise winter scenario), so I'm a bit puzzled.

Late Edit
I might have to reduce this to "if you can see the pipe or get to it to see if it's cracked or may leak and you can switch off the water to this one run without affecting the rest of the house, then warm it now. If not, call the plumber."
What you don't want to end up with is a leak you can't get to & can't switch off without switching everything off, especially if you and a thousand other people are all queuing for the same plumber, who may not be able to make it til Wednesday.

Thawing the pipe is easy enough, a hairdryer or small fan heater & a bit of patience… however…

Ice is 'bigger' than water, so frozen pipes are swollen pipes. Swollen pipes can crack under pressure.
So, before considering your next action - to call a plumber or attempt to DIY - make certain you can see no evidence of swelling or cracking.

If all looks good, then you can gently heat it. If using a hairdryer etc don't get the pipes themselves too warm. Be patient & heat around the area, slow & sure.

  • I would have the water switched off to that line at least when heating it, because if it did crack that's when it will start to leak. This will limit any potential flood. Commented Feb 14, 2021 at 14:40
  • It's very unlikely the PEX would burst, it's amazing stuff. Depending upon how difficult it is to get to the piping to thaw it out and how important that particular toilet is to you, you might just want to "wait it out" and let it thaw on it's own. Obviously keep a close eye on it just in case it did crack, but with pex, it's pretty unlikely. Hopefully some plumbers will weigh in and comment as well. Commented Feb 14, 2021 at 15:24

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