How To Stop Tub From Filling Up When Using Bathroom Sink

A clog in the bathtub drain pipe is a pretty common occurrence that typically happens over time as you begin to notice the water draining slower. This is usually caused by hair clogs, soap scum, or hard water. The drainpipes all connect eventually and a clog may cause the tub to fill up when using the sink and vice versa.

Assess Your Drainpipe Situation

The tub drain is usually a good place to start when you do not know exactly where the blockage is. The P-trap in the bathtub drain can collect sediment and cause a clog over time. If the tub backs up when running water down the sink, however, this is not the issue and the P-trap is clear. There is a clog somewhere but it is beyond the point where the tub and sink drains merge. 

The blockage is most likely several feet below the tub drain and sink in the drain opening may not be a reliable strategy.

Plunging the Bathtub Drain

Plunging the bathtub drain can help dislodge a clog several feet down if done properly. If you just have a screen over your drain and you can fit a plunger around the tub drain you should fill the tub with a couple inches of water, stuff a rag into the overflow tube and also block up the sink drain with a rag or a reliable stopper. This diverts all force to the plunger and the blockage. Get an airtight seal and pump vigorously several times around the tub drain.

If you cannot plunge the tub drain due to an installed bathtub stopper, try snaking through the overflow tube after removing the overflow plate. 

Once you clear the blockage, consider installing a new bathtub stopper with a mesh grid drain cover to help prevent hair and debris from entering your drain. Watco offers an easy to install bathtub stopper and drain cover in one, the SimpliQuick® Tub Fix that can install over any drain, even drains with broken crossbars without removing the existing drain.

Learn more about Watco tub drain parts and tub fix solutions at FixMyDrain.com, your one stop for Watco bathtub drain stoppers and overflow plates. Contact us with any questions and for bathtub fix solutions.