Q&A / 

How To Clear a Clogged Bath Sink Drain

Quick Column Summary:

  • Unclog sink drain without chemicals
  • Start with pliers
  • How to remove stopper and clean it

DEAR TIM: For a month, it’s been taking longer and longer for the water to drain from my bathroom sink. This morning the murky water is just standing there not budging and defying my commands to exit my world and travel into the hidden plumbing pipes. I tried to pull out the stopper, but it only comes up so high and stops. I’m sure if I could pull it out, I’d solve the problem. Do you think I can get the drain unclogged? Do I have to use toxic chemicals? Do I have to take apart the sink trap? Teresia M., Orlando, FL

DEAR TERESIA: There’s a really good chance I’m going to save you some sweet moola. All you need is one simple tool. I’m hoping you have a simple adjustable pliers in your toolbox. This tool will allow you to remove the nut and lever arm that’s holding the sink stopper in place. I doubt you’ll have to take apart the p-trap under the sink. Many people fear this part of the drain line as it always leaks when they reassemble it.

I’ve been a master plumber for nearly forty years and have unclogged countless drains. Some plumbers specialize in this service. In your case, since the slow drain problem has just happened in a month’s time, I suspect your clog is just a mass of hair hung up on the bottom of the sink stopper where it attaches to the lever arm that operates the stopper.

An adjustable pliers is often the only tool you need to clear a clogged bathroom sink drain saving you over $100. Photo Credit: Tim Carter

An adjustable pliers is often the only tool you need to clear a clogged bathroom sink drain saving you over $100. Photo Credit: Tim Carter

There are all sorts of gizmos and magic tools that are sold claiming they can unclog sink drains without removing the stopper. I’ve tried them and it’s like going fishing. You may catch a fish and you may not. The different tools have varying levels of success.

What I like about taking out the stopper is it usually only takes two extra minutes to do this and you have full access to the drain pipe as it leaves the bottom of the sink. Once the stopper is out of the way you can use a flashlight to really see what’s going on.

For you to remove the stopper, and the gross hunk of hair and stuff-I-prefer-not-to-tell-you-about, you need to unscrew a small round nut that’s on the backside of the vertical tailpiece drain pipe that’s at the base of the sink. Before you start this, you’re going to have to get the standing water from the sink.

If you happen to have a wet-dry vacuum, use it. If you don’t, employ a sponge and a bucket. Use rubber gloves to keep your hands dry. The vacuum does a great job because it can often get the water that’s in the vertical drain pipe too.

Once the water is out of the sink, lay on your back and look up at the underside of the sink. You’ll see a short metal rod that is sticking out of the back of the drain pipe. This rod is linked to the knob at your faucet that makes the sink stopper go up and down. When you unscrew the nut that’s surrounding this rod, it will be easy to pull the rod from the drain pipe. Do this and just let it hang. Some small amount of water may come from the pipe, so be prepared to catch it with an old rag.

You can now remove the stopper. Be prepared to be grossed out. There could be a massive slimy hairball attached to it. The stopper assembly will be black with mold and biofilm. If you have any cuts or sores on your hands, you really should wear rubber gloves. You don’t want this gross stuff touching any open cuts, wounds or sores.

If you want to test to see if the sink drains really well without the stopper, hair and gunk in place, you need to re-install the metal rod and the nut. For this test, you can just hand tighten it. I do this all the time. Turn on the water to the sink and it should flow readily down the drain never backing up.

If you’re satisfied the sink is draining well, you may want to do one more thing before you put the stopper back in place after you’ve cleaned it. If you have a bottle brush that’s got a diameter slightly larger than the diameter of the sink drain, I’d recommend you turn on the water to the sink and use the brush to clean the side walls of the vertical tailpiece drainpipe. Any biofilm on this pipe can cause odors and you might as well get it clean now with the stopper out.

Drain-cleaning chemicals can be harsh on plumbing fixtures and you. If you or someone tried to use the liquid cleaners and the stew is still in the sink, do NOT get this liquid on your skin or in your eyes. You must carefully remove and dispose of this toxic brew outdoors before your start to take apart the drain.

If you live in a house built before 1970, there’s a good chance you might have galvanized iron pipe as the branch arm drain line to the sink. Over time, these pipes tend to build up hard deposits that completely choke off the pipe. If this is what you’re faced with, you may have to replace that horizontal pipe between the sink and the vertical plumbing stack that connects to the building drain under your slab or your basement floor. This is a job for a professional.

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12 Responses to How To Clear a Clogged Bath Sink Drain

  1. Looks like good info here...will give to my son.....their bathroom sink drains slow also....thanks for the info.......

  2. I have a shower drain that seems to get clogged every three to four weeks. Presently I am using a chemical to unclog. Is there a better way which wil last linger?

  3. A plunger should work. Be sure to cover the tub overflow when using it, if the shower is in the bathtub. After plunging, get a hair snare to cover the drain while showering and you will be home free. Hope this helps.

  4. any time I put a new stopper in the bathroom sink I turn the stopper upside down and very careful snip .he middle open between the 2 sides so the stopper is not attached to the rod , but install the rod so the stoper rests on it...
    I can clean the drain with a bottle cleaner and baking soda . no other tools are required I do the cleaning every month called maintenance ..

    Mrs. Beer Glendale Ohio

    • You are so right Mrs. Glendale. I have done the same thing and now I am able to pull the stopper out at least once a week. Thanks!

  5. Tim,

    I hate to appear as a negative person, but not all drains work that way. I had a bathroom renovation done a couple of years ago and the fixtures used do not incorporate the same "old fashioned" sink/drain stopper mechanism you describe. There's no knob to pull on, or rod and ball that's removable. The way my sink stopper works is by pushing down on the gasketed stopper in the bottom of the sink. It's spring loaded and has some sort of a catch mechanism, so when you push it down, it holds in the closed and sealed position, allowing the sink to fill and hold water, if desired. Pushing down on it releases the stopper, allowing the water to flow freely down the drain. The only way to unclog the drain without chemicals, or disassembling the traps and pipes themselves is to unscrew the stopper and work from the top down, grabbing whatever junk you can with a long, thin claw like tool. Not so easy and not very effective.

  6. I have used for years a circular diameter brush attached on a heavy wire shaft with the brush small enough that it fits under the stopper, and maneuver the brush between the slatted design of the stopper in the inside of the drain line. The brush will become gunky, so only the strong stomached will care to clean it.

    • This works, but it doesn't remove all of the hair and gunk. If you want to have the drain open like it was the FIRST DAY it was installed, you take out the stopper, flush the drain with water, and then use a larger bottle brush and some soap to clean the sides of the tailpiece that extends down to the p-trap.

  7. Hey Tim!
    I worked in A maintenance shop for 28 years and ,at one time, had A photography department including A dark room. In the dark room there were several sinks that had glass waste lines on them. When we got rid of the photography dept. I took the glass p-traps and used them in my house. Now I can see if there are any clogs starting to form and flush them out before they cause A major problem.
    I also like to put A cup of baking soda followed by A cup of white vinegar down the drain's once A month to help keep the drain's clear. I leave it work for several minutes and than flush with the hottest water available for at least 10 minutes.
    Not to wish you bad luck on your May 2nd. guess of final snow melt but my 62nd. Birthday is May 3rd. So I'm going with that! Ya wanna take A guess on final snow date for my state of MN.? (Hint... It's snowing right now!) I'm going with the 4th. Of July!!
    Good luck!

  8. Mr. Carter, I have little trick for bathroom drains. If running slowly or not at all, I will go down as far as I can with snake and it may start to drain a tiny bit. Run in some hot water and let it ease its way down which may take some time, even an hour or more. Then I put 1 cup of warmed, full-strength pine cleaner in the drain and leave it for as long as it took the water to ease down. Lo and behold, I can either get the glob right up or the snake right down or it just cleans itself out.

  9. "This is a job for a professional." Scares me. Competence and professional are not synonyms. For us in the hinterland competence is hard to find. I do believe a couple of girl scouts with a pipe wrench could replace the pipe.

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