How to Unblock a Sink (Kitchen or Bathroom)

A blocked sink is one of life’s more irritating domestic problems. Whether it’s water refusing to drain or a foul smell rising up from the plughole, you’ll want to sort it fast. The good news is, most minor blockages can be cleared at home with tools and ingredients you already have.

Here’s how to fix it — step by step — and avoid an expensive call-out if you can help it.

Step 1: Boiling Water (Yes, Really)

Start simple. Boiling water can often loosen grease and soap scum, especially in kitchen sinks where food fat is the culprit.

• Boil a full kettle

• Slowly pour the water directly down the plughole

• Wait a few minutes and repeat if needed

This works best for slow drains, not complete blockages.

Step 2: Use Baking Soda and Vinegar

This natural method works well for mild clogs caused by grease, soap, and grime.

1. Tip half a cup of bicarbonate of soda down the plughole

2. Follow with half a cup of white vinegar

3. Cover the plug with a damp cloth or stopper

4. Let it fizz for 10–15 minutes

5. Flush with boiling water

It’s chemical-free and surprisingly effective for smaller build-ups.

Step 3: Try a Plunger

A plunger can shift blockages by creating suction. You’ll need enough water in the sink to cover the rubber cup.

• Place the plunger firmly over the plughole

• Push down and pull up sharply for 20–30 seconds

• Release and check if the water drains

If you’ve got a double sink, block the second drain with a cloth or plug while plunging to maintain pressure.

Step 4: Check the U-Bend

If the blockage is stubborn and nothing’s shifting it, the problem may be in the U-bend (the curved pipe beneath the sink). You’ll need:

• A bucket

• A wrench or pliers

• Old towel or cloth

Place the bucket underneath, unscrew the pipe, and empty the contents. Clear any gunk, then rinse the U-bend and screw it back in. This usually does the trick for physical blockages like food or hair clumps.

Step 5: Use a Drain Snake or Wire

If you suspect the blockage is deeper in the pipe, a drain snake (also known as a plumber’s auger) can help. Feed it down the plughole, twist, and pull out anything lurking in the pipe.

If you don’t have one, a straightened wire coat hanger can work — just be gentle to avoid damaging the pipe.

When to Use a Chemical Drain Cleaner

As a last resort, you can try a commercial chemical unblocker — available at most supermarkets and DIY shops. These are powerful and should be used with care:

• Wear gloves and open windows for ventilation

• Never mix with other cleaners (especially bleach)

• Follow the instructions exactly

Only use these occasionally — regular use can damage pipes over time.

When to Call a Plumber

Call in the pros if:

• None of the methods above worked

• Water is overflowing or leaking from pipes

• The blockage keeps returning

• It smells like something has died in your drain (seriously)

Sometimes, deep or serious blockages need specialist tools or a camera inspection.

Final Thought

Most sink blockages are caused by a build-up of hair, food, grease, or soap — and they can usually be cleared with boiling water, baking soda and vinegar, or a good old-fashioned plunger. Keep on top of sink hygiene to stop clogs forming in the first place, and save yourself the faff next time.