Where I live in Texas, we still get 6 weeks a year of freezing temperatures. During those weeks my mother never fails to call and remind me to let my bathtub faucet drip so the drain doesn’t freeze.
A bathtub drain can freeze if there’s standing water in the trap or anywhere in the line. Standing water can happen if there’s a clog of debris or minerals causing water to pool. A bathtub drain can also freeze if there’s a slow drip from the faucet or leak in insulation that allows wind to hit the pipe.
So it turns out the conventional wisdom about letting faucets drip during a freeze is not actually good—as the drip is so slow into the pipe, it actually has a better chance of freezing there than if you ran a full stream of water from the faucet.
In this post, I’ll explore why a bathtub drain can freeze, how you can distinguish between a frozen drain and a clogged drain, and how you can fix a frozen bathtub drain without ruining it.
Why a Bathtub Drain Might Stop Working
So your bathtub drain stopped working, and maybe it’s really cold outside. You decided the drain is probably frozen. It’s a good guess but how can you be sure?
It’s possible your drain stopped working for other reasons. Before you can treat the problem, you need to know what it is and if the drain is frozen, where exactly is the ice?
Hairball in Trap or Frozen Bathtub Drain?
It’s not uncommon to have a hairball clog your drain, especially if you have a long-haired person using the tub.
Gels and Conditioners
And it’s not just the hair itself which can get into the pipe and clog it. It’s the products that many long-haired girls and women like to apply to keep their locks shiny and gorgeous. (It’s worth it, though!)
But did you know some gels and conditioners will expand in the cold? So if you add cold weather to the product plus the hair, you’ve got enough to clog the drain.
Slowly Draining Water
Suspect a hairball rather than a frozen bathtub drain if you’re getting some water to drain, but it’s just going out of the bathtub slowly. The reason is that the water passing down the pipe would likely warm any frozen mass in the pipe, and since you are able to drain some water, there’s probably not a frozen mass.
Try Tools or The Green Gobbler
If this is the case, remove the drain plate. Use a flashlight to peer into the drain. If you can see the hairball, use a flat-nosed pliers to remove it. However, if the hairball is not visible, try a drain auger or drain zipper.
A drain auger is a cable that you send down the drain and then bring back up in a twisting motion to clear any blocks. (If you have a drain snake, a drain auger is the same thing but made for a smaller drain like a sink rather than a bathtub. The cable used in a drain auger is a bit thicker.)
A zipper is a long plastic tool with angled barbs on it. You stick it down the drain and it pulls up the muck.
Or you can try a product like the Green Gobbler, which dissolves hair, soap and grease in pipes by using sodium hydroxide. It’s less toxic—and can be more effective—than old standbys like Drano.
Mineral Deposits in Pipes or Frozen Bathtub Drain?
If your pipes run horizontally, they are prone to collect mineral deposits of calcium, potassium or magnesium.
Usually, this happens if you have hard water running through the pipes to your fixtures. Look for hard white buildup on your toilet and tub as evidence. If you suspect a mineral buildup in your pipes, you can try pouring vinegar through the pipes and leaving it there for 24 hours.
However, if the deposit is substantial, you’ll need a different solution. In that case, you may have to get a water softener or replace your metal pipes with plastic pipes that are resistant to mineral deposits.
Yes, It’s a Frozen Bathtub Drain!
If you’ve ruled out the other possibilities and you’re confident that you simply have a frozen bathtub drain, then there are some DIY solutions that can save you the cost of a plumber.
The caveat here is that these solutions will only work if the frozen mass isn’t too far down the piping from the tub.
Drain and Overflow
Let’s take a second and talk about the anatomy of your bathtub drain. At the bottom of the bathtub is the drain. It’s covered by a “drain cover.” You might flip a switch to make it open and close, or you might step on it to create suction and then pull it up, in order to drain water.
On the side of the tub, underneath the spout is what’s called the “overflow pipe.” This is what sucks out water from the tub when the waterline gets too high. The overflow pipe protects the bathwater from overflowing onto the floor.
The overflow pipe runs down the back of your bathtub and meets up with the drainpipe that is sucking water out from the bottom of your tub. The drainpipe runs about a foot before it loops around in the shape of a letter “p.”
The loop of the pipe is called a P-Trap. This loop can prevent sewer gases from entering your home. It’s also a place where a pipe is likely to freeze or get clogged, since the loop of the P always contains water.
If the freeze has happened in the overflow pipe or drainpipe before the P-trap, you may have success trying some DIY options to melt the ice causing the blockage. However, if the problem is further down the pipeline, you may need to call a professional. But you might as well try these simple solutions first.
How Did You Cause the Bathroom Drain to Freeze?
Not to make you feel guilty, but it’s possible you did or didn’t do something important during particularly cold weather that caused the problem. By identifying your actions that are to blame, we’ll help you avoid making the same mistake in the future.
So here is what you need to ask yourself:
- Did you leave the faucet on drip to prevent freezing pipes? If yes, don’t do that again.
- Did you turn off the water before a freeze, without letting any water already in the pipes drain out? If yes, that could leave a puddle standing water in the pipes vulnerable to becoming an ice ball.
- Do you turn down the heat so much to save money that the house is frigid, but you’re toasty warm under the covers? This plan can backfire, since a burst pipe will cost you more than what you save by turning down the heat.
- Do your pipes run through a poorly insulated attic or uninsulated crawl space. Pipes are vulnerable to freezing when they’re hit by cold air–even on a tiny part of the pipe.
The fact of the matter is that water expands. Even a little bit in the pipe during a freeze can have a truly costly impact if it causes a pipe to burst. According to fixr.com, in the US, repairing a burst pipe costs an average of $500. And that doesn’t include fixing any water damage that resulted from the leak or flood.
A clue that you have a frozen bathtub drain and not a hairball down there in the pipe can also be that the water is pooling up around your feet when you run the bathtub. But it’s not draining at all.
How to Immediately Fix a Frozen Bathtub Drain
There are two DIY methods that you can use to fix a frozen bathtub drain. We’ll start with the easiest and work our way up:
A Nontoxic Recipe to Fix the Frozen Bathtub Drain
When I was younger, I used to make mini-volcanoes in the backyard out of white vinegar, baking soda and water. Well, you’re going to make a little volcano erupt inside your drain.
- Pour ½ cup of dry baking soda down the drain
- Dissolve 1 cup of table salt in 2 gallons of boiling water
- Pour 1 cup of white vinegar down the bathtub drain. Now you’ve created the mini-volcano that should break up any ice, so long as the blockage is between the tub drain and the P-trap and not further out in the pipe.
- Now pour the saltwater solution down the drain to melt any chunks of ice.
Warning: You don’t want to substitute any unknown chemicals in this recipe because you could cause a chemical reaction that not only bursts your pipe, but also flies up through the drain and hits your face.
Warming the Pipe
To unfreeze the drain pipe, try warming it up. But first this warning.
Warning: Obviously electricity and water are a dangerous combination. Be careful and never use an open flame to try to warm your pipes.
Hot Air, Hot Water Bottle or Heat Tape
Try warming the pipe by removing the stopper and flooding the pipe with hot air. How? Use a hairdryer and shoot the air directly into the drain.
If you are lucky enough to have an access panel, you can try to blow dry the side of the pipe there or even warm the pipe by wrapping it with a hot water bottle.
You can also try wrapping a metal pipe with heat tape.
Warning: Since heat tape is electrical, be sure it’s not going to come in contact with water from a leak. Note that heat tape can damage a plastic pipe.
Sometimes your bathtub has an Access Panel. It looks like a little cabinet on the side of your bathtub that allows a plumber to more easily access pipes without needing to dig into existing walls or flooring.
You’ll more readily find an access panel on a newer bathtub, a drop-in bathtub or a jacuzzi tub. And you’re less likely to see one on an older bathtub or an alcove tub. (If you’re not sure what tub type you have, check out this post on bathtubber.com. If you need to contact a plumber to help with the drain, this is helpful information to relate.)
Warm the Vent Pipe
You might also try to warm the vent pipe (also called a vent stack). This is the pipe that leads out of the house. It’s purpose is to supply your plumbing fixtures with fresh air. It will remove any odorous or toxic air from your home.
In order for your bathtub to drain, the vent pipe needs to be funneling fresh air into the drain system. However, if the vent pipe is frozen, then it can’t do it’s job and your drain could get stuck.
If you’re really handy (and not afraid of heights), go into your attic and see if the vent pipe is frozen. You can warm that up using the same method you would that I suggested to warm the drain.
What If Your Bathtub Drain Is Still Frozen?
If your drain is still frozen you can call a plumber. According to homeadvisor.com, expect to pay $42-$200 per hour, depending on where you live.
The plumber might go into your crawl space, and will look for places where your pipes might be exposed to wind. In a worse case scenario, the plumber may need to get into the plumbing wall by breaking into your drywall, floor or ceiling.
Prevent Your Tub Drain From Freezing Again
Once you go through the trouble of trying to melt a frozen bathtub drain, you’ll be more willing to take preventative measures. You do want to ward off the problem from recurring in the future, right?
So what can you do in cold weather?
- Keep the inside temperature above 65 degrees Fahrenheit.
- Open cabinets with pipes and bathroom doors to circulate the air.
- In anticipation of a freeze, turn off the water lines and be sure to drain the water still in the pipes.
- Inspect the water lines that run to your bathroom and the drainpipe and vent stack. If any of these run through uninsulated attics or crawl spaces, consider adding more insulation.
No Need to Ruin Your Bathtub Drain
Even if your bathtub drain froze, there’s no need to ruin it. Simply remove the stopper, if you have one, and try the DIY techniques above. If you have a drain basket covering the pipe, you don’t need to remove it at all before using the mini-volcano or hairdryer techniques.
Once you melt the ice block in your bathtub drain, you’ll be able to hop right into a steamy bath. All your worries will instantly melt away. On a freezing cold day, there’s nothing better!