Site Banner Graphic

How to Unclog a Bathroom Sink Drain

Dealing with Bathroom Sink Stopper Assemblies and Overflow Drains

Pep Talk

Bathroom sink clogs are probably the most common type of household blocked drain. The levered drain stoppage assembly snares the ubiquitous hair in a congealed mass of toothpaste and soap scum. It is for this reason that our first piece of advice is to delegate this responsibility to a teenager. That’s right, make the nearest teenager come finish this article and unclog the darn sink for you. Then tell them they have to keep it clean from now on. It is still our recommendation that you do this, even if you have long hair and the teenager has short hair, because teens need to learn a lesson about life and buildup of gunk in pipes.

Undersink Preparation

Whoever has to do it, to unclog a bathroom sink you first need to remove the pop-up stopper from the sink drain. Often a wiggle and pull will free the stopper from the drain, but it may require you to go below the sink to unhook it. Never force it or exert too much pressure. These parts are very often chrome plated plastic, and will break. Consult the fixture owner’s manual if you can find it to see how yours works specifically, but most follow the same design. Underneath the sink, the bar connecting the pull rod to the stopper needs to get out of the way. Usually one end will be loosely clipped to an adjustment hole in the pull-action rod, while the other end goes into the drainpipe and hooks the stopper device. It enters the drainpipe through a large nut called the pivot nut, and it is this nut you must loosen to free the rod to unhook the stopper so you can pull it out.

Loosen the pivot nut carefully; you should not need to remove the nut completely. Once loosened the horizontal bar can be slid out from the drain freeing the stopper. To reassemble, jiggle the stopper up and down while reinserting the rod, so you can feel when you have the rod through the hook or hole. You must still retighten the pivot nut, or your sink will leak! If you do not reassemble the bathroom popup assembly correctly and leave the stopper unhooked, the lever will not be able to pull down on the plug to help form a seal for filling the basin, but may otherwise serve its purpose.

The Reveal

Very often much of the clog will come out with the stopper piece. What remains is usually stuck on a small straining screen just below the stopper linkage and above the U-Trap. A bent stiff wire can be used to snag the bits left in the drain. Long pointed needle-nose pliers are the other obvious tool for the job.

It is fortunate that the extra screen in the drain and the complex stopper catch so much of the hair, soap, oil, and so on that comes down the bathroom drain. If they did not, they clog would form somewhere else out of reach of pliers or wire, and plungers are infrequently helpful when it comes to bathroom sinks.

You should only attempt to unclog a bathroom sink using the plunger as a last resort. In the case of bathroom sinks also called lavatories, the sometimes multiple overflow outlets and complex stopper linkages alongside tightly curved sink bowls makes forming the requisite seal with a plunger shaped for a different job nearly impossible.

With bathroom sinks, if they are still draining slowly after cleaning the stopper linkage and screen in the drain, the next suspect area is the U-trap immediately below the sink, and the pipes leading away from it. The U-trap can often be removed, the pipes cleaned, and the trap replaced with little effort, but these pipes are not typically heavy duty plumbing pipes, they are fragile, and can crack if banged, twisted, or over-tightened. Use a wrench big enough to work the large nuts without damaging them.

Winding Up

Cleaning the bathroom sink drain is not a pleasant job, but need not take more than several minutes to restore free flow, and less than that for maintenance. Keep your pivot nut threaded with Teflon tape, and you can loosen or tighten it by hand without a wrench. Always check for leaks with full flow of water through the drain before cleaning up and putting away your tools.The final option before calling in the pros is a handheld drain auger--a stiff coiled cable with a weighted end that can be twisted into pipes, boring a clear path.  Bathroom sink porcelain and chrome is easily scratched and permanently marred by rough metal cable, so if you decide to use an auger on your sink drain, do so with caution, and cover any exposed surface with plastic or cloth. Another approach is to remove the U-trap in any case, and feed the auger cable through the pipes from under the sink, avoiding polished surfaces.