Basic ASF

How to unclog a drain without wrecking the pipes

Basic ASF ยท

The short version

Start mechanical, not chemical. Pull out and clean the stopper, plunge with a cup plunger while blocking the overflow, then use a cheap plastic drain snake or clean the U-shaped trap under the sink. Avoid mixing chemical drain cleaners, and call a plumber if several drains are slow at once.

Most blocked bathroom drains are hair and soap. Most kitchen blockages are grease and food. Both usually come out with tools you can buy for very little.

Before you start

  • Don't pour in chemicals first. If they don't work, you're left plunging a sink full of caustic liquid.
  • Put on rubber gloves. Have an old towel and a bucket nearby.
  • If you already used a chemical drain cleaner, don't plunge or snake; splashback can burn. Flush with plenty of water first and follow the product label.

Step 1: Clean the stopper

Many bathroom sink and bath stoppers lift or twist out. Pull it out and remove the hair wrapped around it. This alone fixes a lot of slow drains.

Step 2: Plunge

  1. Use a cup plunger (flat bottom) for sinks and tubs. The flanged kind is for toilets.
  2. Fill the basin with enough water to cover the plunger cup.
  3. Block the overflow hole with a wet cloth, or the pressure escapes through it. For double kitchen sinks, plug the other drain.
  4. Push down gently to seal, then plunge firmly up and down 15 to 20 times, keeping the seal. Pull off sharply at the end.
  5. Repeat a few times before moving on.

Step 3: Snake it

A plastic barbed drain strip, sold cheaply in hardware stores, is made for hair clogs. Push it down the drain, wiggle, and pull it back up slowly. A small hand-cranked drain auger works for deeper clogs.

Step 4: Clean the trap (sinks)

The U-shaped pipe under a sink, called the trap, catches debris.

  1. Put a bucket underneath.
  2. Unscrew the slip nuts by hand (or with pliers if tight).
  3. Remove the trap, empty it, and clean it out.
  4. Reassemble, hand-tighten, and run water to check for leaks.

What about hot water, baking soda, and vinegar?

  • Hot tap water can help soften grease and soap.
  • Boiling water can damage PVC joints and crack porcelain, so skip it with plastic pipes or toilets.
  • Baking soda and vinegar fizz impressively but have limited power on real clogs. It won't hurt to try, but rely on the mechanical steps.

Never mix cleaning products

Mixing drain cleaners with each other, or with bleach, ammonia, or acids, can produce toxic gas or violent reactions. Use one product at a time, follow its label, and ventilate.

When to call a plumber

  • Several drains are slow or gurgling at once, which may mean a main line blockage.
  • Water comes back up in another fixture when you run a tap.
  • There's a sewage smell or a leak you can't stop.
  • Nothing above has worked.

Limitations

Plumbing differs from home to home. If you rent, check your lease; your landlord may be responsible for blockages. Also see How to do laundry.