How to unblock a drain: Simple DIY methods to try first

You might be washing up or enjoying a shower when you notice the water draining more slowly than usual. It’s frustrating — and it can leave you worrying about costly plumbing bills or being without a working sink or shower for days.

In many cases, a slow drain simply means there’s a blockage somewhere in the pipework. Before calling a professional, it’s worth trying a few simple fixes at home.

Here are some practical ways to unblock a drain in the UK.

1. Use baking soda + vinegar

This is a popular, natural method that works well for mild blockages in kitchen and bathroom sinks.

What you’ll need:

• 80ml (about ⅓ cup) white vinegar

• 80ml (about ⅓ cup) baking soda

What to do:

1. Pour the baking soda directly down the drain.

2. Follow with the vinegar — it will immediately start fizzing.

3. Leave it to sit for at least one hour. For best results, leave it overnight.

4. Flush through with hot (not boiling) water.

The fizzing reaction can help loosen grease, soap scum, and minor debris.

2. Pour boiling water down the drain

Hot water being poured into a stainless steel sink drain for drain cleaning (Source: iStock)

For grease-related blockages (particularly in kitchen sinks), boiling water can sometimes do the trick.

How to do it:

1. Boil a full kettle.

2. Carefully pour the water down the drain in stages, pausing for around 10 seconds between pours.

This method works best on fat, oil, or soap buildup.

3. Try salt + baking soda

This is another household remedy that may help break down minor blockages.

What you’ll need:

• 120g (½ cup) baking soda

• 120g (½ cup) table salt

Steps:

1. Mix the salt and bicarbonate together.

2. Pour the mixture down the drain.

3. Leave it for 10–20 minutes.

4. Flush with boiling water.

This combination can help loosen grime and buildup inside the pipe.

4. Use a plunger

Sometimes a traditional plunger is the most effective solution.

Tips for best results:

• Make sure there’s enough water in the sink to cover the rubber cup.

• Seal any overflow outlet with a damp cloth.

• Ensure the plunger fully covers the drain opening.

• Pump firmly up and down several times to create suction.

It may take a few attempts, but plungers are highly effective at shifting many common blockages.

5. Use a chemical drain cleaner

Applying chemical drain cleaner to a clogged bathtub drain (Source: iStock)

If natural methods haven’t worked, you can try a chemical drain cleaner from a supermarket or DIY store.

Follow the manufacturer’s instructions carefully, including:

• Wearing gloves

• Ensuring good ventilation

• Leaving the product in for the recommended time

Afterwards, flush with hot water.

6. Try an enzyme-based (organic) cleaner

For a more eco-friendly option, enzyme-based drain cleaners use natural bacteria to break down organic matter, such as:

• Hair

• Soap residue

• Food waste

• Grease

These products tend to work more slowly than chemical cleaners but are gentler on pipes and the environment.

7. Clean the U-bend (sink trap)

If the blockage is under your sink, it may be trapped in the U-shaped pipe (also known as the trap).

You’ll need:

• A bucket

• Adjustable spanner or wrench

• Old toothbrush or cloth

Steps:

1. Place the bucket under the pipe to catch any water.

2. Loosen the slip nuts at both ends of the U-bend.

3. Carefully remove the pipe.

4. Empty and clean out any debris.

5. Rinse thoroughly and reattach securely.

Make sure all connections are tightened properly before running water again.

Have your drain unblocked with Airtasker

If DIY solutions haven’t solved the problem, you can find experienced plumbing professionals on Airtasker who can quickly diagnose and clear your blocked drain.

Post your task, compare quotes, and get your sink, shower, or bath back to full working order without the stress.