Frozen Tub Drain?

Question

We have had below freezing temps for about a week or so. The drain in my tub has been freezing periodically, but usually opens up if I put a bit of table salt down the drain. However, it's been extremely cold the last couple of days, and the drain is now frozen and nothing seems to help. My fiance thought it would be a great idea to fill the tub with hot water to get it to melt but that didn't work. Now we have a tub full of cold water, with a frozen drain. How do I getthe drain opened?? HELP!!

I should add too, that we have no electrical outlet that would be a handy source to get a dryer or such down under the crawl space to the drain.

Answer 1

My kitchen / bathroom drain has frozen up...
The main thing to remember about freezing and pipes is that water expands as it freezes. It "gets bigger". Pipes which burst due to a severe frost actually burst as they freeze, but you only get the message as they thaw afterwards. Ice can't leak...water can. Of course, water also expands as it warms up - that's why your central heating system will probably have something called an "expansion tank". This also accounts for sea level rises due to global warming. Water actually has it's maximum density at about 4 degrees Celsius...the temperature found at the bottom of many deep lakes.


When I try to thaw out a frozen drain pipe I start from an end...usually the "top" end. I put an egg-cup full of cooking salt - sodium chloride - Na Cl - down the drain. Salt water is denser than fresh water, so it sinks to the bottom. I know there is water already in the sink - that's how you became aware of the freeze-up...but if you can't / choose not to remove it, simply pour the salt over the plug hole area and it should do its work. Salt water - like sea water - freezes at a lower temperature than fresh water, so the salt will usually flow down and cause the ice to thaw out as it becomes salty. Give it a while - 15 minutes say - then add more salt if necessary. You should be rewarded with occasional crunchy noises as the ice melts.


What else can you try? A hairdryer or an electric heat gun can be applied with care to metal pipes, and plastic ones too, but don't melt the plastic. Again, try to work from an end, rather than from some point in the middle. Forget blow lamps and other portable flame machines unless you know what you are doing. If you heat the middle section of a frozen pipe, you could conceivably cause it to burst due to localised expansion of the water.


I have also inserted a rubber hose pipe down the drain as far as it will go, and poured hot water down it, but that was only because I didn't have any salt!


Once the drain is flowing, pour some hot water through it to clear the remaining ice. If further freezing temperatures are forecast, put some salt down the sink / bath drain last thing at night to try to prevent the same thing happening in the morning. You could also "lag" the outside parts of the drain where the water comes out by covering it with some plastic shopping bags, or a bin liner, filled with screwed up newspapers, and tied shut. This will act like a blanket to keep the heat in. Weigh it down to stop it blowing away.

Answer 2

Frozen Drain Pipe

Answer 3

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If you can access the pipes from below, get a hair dryer and aim it at the drain for awhile. I would suggest using boiling water, not just hot. but it seems you may have standing water mixed with drain cleaner already sitting in the tub making it unsafe to bail. If there is no drain cleaner, I would remove all the standing water and use boiling water down the drain. I would also suggest getting the drain insulated so you don't have this problem in the future.

Answer 4

got a stand up shower in my cottage...when temps got to 10 below had a drain freeze...the cottage is only 2 1/2 feet of the ground, so runoff is very poor. It's virtually impossible to get a good angle and water often collects. So when this happens, I also boil water with salt, pour it down the drain and use a plunger to force the hot salted water to penetrate the frozen drain, gradually the standing water in the shower begins to leave, and within a half hour the drain opens. The boiling water and salt are very potent against ice, but the key was plunging.....it seemed to have doubled the speed of the melting process.

Answer 5

Our tub drain froze two days ago when our windchill hit -40 some, and we just found this article and tried the salt, and our drain was clear in a matter of minutes!!! Wish I would have found this earlier!

Answer 6

The salt was a miracle worker...thanks everyone!

I first bailed out most of the water then poured as much rock salt as the drain could handle before having a slow drip of hot water (I'm sure the boiling pot of water would work great too but I was too lazy to go back downstairs to boil some). I went downstairs to make lunch, returned in 20 minutes and everything was cleared!

Now, I will remember (again) to keep a slow drip of hot water to keep the pipes flowing during these sub-zero temps!!!

Answer 7

What can I put in the tub drain to prevent it from freezing? Baby oil, anti-freeze ????

Answer 8

pour some drain-no down the drain don't worry about the tub being full it Will sink to the water the drain-no has a chem. reaction makes it heat up melting the ice

Answer 9

Removed as much water from the tub as possible. Poured the salt down and it took just under 15 minutes ! This post was a life saver! Thanks!

Answer 10

Are you positive that it is frozen and not clogged? Hot water would probably melt the ice in the pipes and it would drain properly. Id suggest trying some sort of drain opener

Answer 11

This has just happen to me. I put table salt down the drain and in about 10 mins. The drain was draining again. Thanks for all the help. P.S. The wind chill factor reach -46 last night. Man it was cold.