We've just had a bad cold spell, including temps down to 9 deg F 2 consecutive nights and 12 last night. Temps this low are very unusual here, the lowest I can recall in 17 years here (Corvallis, Oregon), where we may get snow once a winter that usually is gone within a day or 2.

I have left water trickling in 2 sinks each night.

Yesterday morning the shower and toilet worked fine at first, but as I showered, the water backed up in the tub, then drained out without any help before I finished. The toilet was bubbling and overflowed when flushed once. The rest of the day everything worked fine

Today the water didn't drain from the tub, so we didn't flush the toilet. Late this afternoon I bailed out the full tub, then began pouring boiling water down it's drain. (The water level in the toilet went down as I bailed and it went up slightly when I ran the kitchen faucet.) It finally drained, so we flushed the toilet--and had a mess to clean in spite of plunging. And the drain is not working again. I've continued with the boiling water and it finally just went down again after sitting a while, but now it's bed time, so we'll leave it until morning.

Is this likely a problem with the vent that I read here?
Temps are rising to around freezing... hopefully it will fix itself.
If not, can we pour hot water into the vent? Do we need to use a hose?

Thanks!

Okay, sounds like Oregon has had there share of a cold snap.

There possible could be a problem with the cold in relation to supply pipes. Keeping your faucets open a little was a good idea, but I am not sure about your drain pipes having an "freeze" issue. That would depend.
You could try your vent. But the amount of water back up would indicate to me that this would be drains and a clog. Where are your drains located? Meaning, do you have a crawl space under your home? It might get cold enough to firm up anything in your drain pipes, but it is hard to know for sure from this post.

You may have to try to snake your lines first. Can you give info on your home in relation to your drain pipes?
"On slab" Crawlspace, or basement?

Hopefully it will warm up enough today to unclog your drains. If not hot water down the vent may put you back in business. If you're going to use the hose I would connect it to the boiler drain on the water heater.
Good luck and stay warm. Tom

Temp is 32 deg F and raining. High forecast is 34 or 35.

This morning we put more boiling water in the tub, then ran the shower, then more boiling water. The water went down the drain, but water also bubbled in the toilet (and water level rose in toilet).

We have a crawl space and only some (half?) of foundation vents are covered, thus why I left faucets dribbling.

Hose from water heater to vent isn't realistic; tea kettle of boiling water (or bucket of hot) to roof could be done. How do I tell which vent is for water (vs. fan)? Smaller diameter pipe?

Clog (other than ice) seems very coincidental with hard freeze. Or could the freezing move stuff around?

Thanks!


Water still not draining out of tub (after more boiling water).

More info/questions:

-Is there any reason why I can't pour hot water down the vent instead of using a hose down the vent?

-Our crawl space is not easy to get to, entry is in our closet, LOTS of stuff in there and the bedroom. (We outgrew our house a long time ago!)

-I realized the fan may not be a pipe or, if it is, we could run it to see which is which.

Thanks!

A plumbing vent will be covered by a "boot" with an opening on top. It is long like the pipe would be. A fan exhaust should not look anything like a pipe.

The hose method is because it is easier. Bringing something like a bucket or hot tea pot is dangerous to try to bring up and doesn't have enough pressure - or long enough water stream.

It is possible that some things in the pipe have gotten a litter frozen, and now causing more of clog then there was before. Not a soft clog now, in other words.

You will still need to snake that line regardless. If you need to move things out of your closet - there is no way around it really. One of those "have to" situations. Get the snake like we suggested above - or wait until you defrost, which may or may not solve your problem.