Unclog a Slow Drain in 4 Steps

A slow bathroom drain is usually a plug of hair and soap within reach of a plunger or a short hand snake — no chemicals required.

Start at the stopper. Most basin clogs live on the pop-up stopper itself or in the first bend of the trap, within arm's reach. Remove the stopper, clear what is hanging from it, and run the tap — a surprising share of slow drains end right there.

Step two is the plunger. Block the overflow hole with a wet cloth, fill the basin with enough water to cover the cup, and plunge with steady strokes for 20-30 seconds. The cloth in the overflow is what turns splashing into actual pressure on the clog.

Step three is the hand snake. Feed the cable into the drain until you feel resistance, rotate the handle while pushing gently, then withdraw — the clog usually comes out wrapped around the tip. Hand snakes for household drains carry 3-6 m of cable: 3 m reaches the trap and the near branch line, while 6 m covers clogs that have travelled further down the run.

Step four is the flush: run hot water for a minute to carry loosened debris away, then watch the drain rate. If the basin still drains slowly after snaking, the blockage sits beyond the cable's reach and the job stops being a hand-snake job.

Chemical drain cleaner is the wrong tool in three common cases: when the drain is fully blocked and the cleaner just ponds on top of the clog; when you plan to snake afterwards, because the cable will splash caustic liquid back at you; and when the same drain clogs repeatedly, which signals a mechanical snag that no chemical will dissolve.

• Remove the stopper and clear the hair hanging from it.
• Block the overflow, then plunge for 20-30 seconds.
• Snake with a 3-6 m hand cable until the clog comes out on the tip.
• Flush with hot water for a minute and check the drain rate.

Further reading

• Fix a Dripping Faucet
• Toilet Parts Size Chart