How to Unblock a Sink (UK DIY Guide)
A blocked sink is a common issue in both kitchens and bathrooms. Most blockages are caused by grease, food waste, hair or soap build-up and can often be cleared without calling a plumber.
This step-by-step UK DIY guide explains how to safely unblock a sink using simple tools and when the blockage requires professional attention.
Tools You’ll Need
- Rubber plunger
- Bucket
- Adjustable spanner
- Screwdriver (if required)
- Wire coat hanger or drain snake
- Old cloths or towels
Materials Required
- Baking soda
- White vinegar
- Washing-up liquid
- Hot (not boiling) water
Step 1: Check for Visible Blockage
Remove the plug and inspect the plughole.
Use gloves to remove visible debris such as hair or food waste.
If water drains slowly, the blockage is likely further down the pipe.
Step 2: Use a Plunger
Place the plunger firmly over the drain opening.
Run a small amount of water into the sink.
Pump vigorously for 20–30 seconds.
Check if water begins draining normally.
Repeat if necessary.
Step 3: Try Baking Soda and Vinegar
Pour half a cup of baking soda down the drain.
Follow with half a cup of white vinegar.
Cover the drain and leave for 15–30 minutes.
Flush with hot water.
This method helps break down grease and soap residue.
Step 4: Remove and Clean the Trap (U-Bend)
Place a bucket under the sink.
Unscrew the U-bend (trap) carefully.
Empty contents into the bucket.
Remove any trapped debris.
Reassemble securely before turning water back on.
Step 5: Use a Drain Snake
Insert the drain snake or straightened wire hanger into the pipe.
Twist gently to catch debris.
Pull out slowly.
Flush with hot water to test drainage.
Common Mistakes to Avoid
- Pouring boiling water into PVC pipes
- Overusing chemical drain cleaners
- Forgetting to place a bucket under the trap
- Forcing the pipe fittings
- Ignoring recurring blockages
Repeated blockages may indicate a deeper issue.
When to Call a Professional
You should contact a professional if:
- Multiple drains are backing up
- Water is overflowing
- There is a strong sewage smell
- Blockage returns quickly
- Outdoor drains are also affected
See our Blocked Drain Repair Cost Guide for typical UK pricing.