What to Do If you have an Overflowing Sink: A Guide
An overflowing sink is one of the most common—and stressful—household plumbing problems. Whether it’s in the kitchen, bathroom, or utility room, water backing up can damage floors, cabinets, and personal belongings if not handled quickly.
Knowing what to do immediately can minimise water damage, save money, and stop the problem from getting worse.
What to Do Immediately if You Have an Overflowing Sink
If water starts rising in your sink, act fast:
1. Turn Off the Water
- Turn off the tap straight away
- If water continues to rise, shut off the isolation valve under the sink. If not available, you may need to isolate via the mains stopcock. Homeowners and tenants should know where their stop cock is and ensure it is accessible.
This prevents additional water from entering the system.
2. Protect Your Home
- Remove items stored under the sink
- Use towels, cloths, or a bucket to contain the water
- Prevent spread to floors, cupboards, and nearby rooms
3. Stop Using Other Appliances
Avoid using:
- Washing machines
- Dishwashers
- Other sinks connected to the same drainage system
This can worsen the blockage if pipes are shared.
Simple DIY Fixes You Can Try Safely
Before calling a plumber, these low‑risk steps may clear minor blockages.
Use a Plunger
A sink plunger can often dislodge small blockages.
How to do it properly:
- Ensure enough water covers the plunger head
- Block the overflow hole with a wet cloth
- Plunge firmly several times
Clean the U‑Bend (Trap)
If you’re confident:
- Place a bucket underneath
- Unscrew the U‑shaped pipe below the sink
- Remove debris and rinse thoroughly
- Refit securely
This is especially effective for hair or food blockages
What NOT to Do When You Have an Overflowing Sink
To avoid injury or costly repairs:
- Don’t use chemical drain cleaners (they can damage pipes and cause burns)
- Don’t force water down the sink
- Don’t dismantle pipework unless you’re sure how to reassemble it
Incorrect fixes can lead to leaks and long‑term plumbing issues.
When to Call a Professional Plumber
You should contact a plumber if:
- The sink continues to overflow after DIY attempts
- Multiple drains are backing up
- You notice bad smells or gurgling sounds
- Drainage is slow throughout the house
- Water is leaking or causing visible damage
Plumbing issues can escalate quickly, and professional help is often the safest option.
👉 To find a qualified, SNIPEF‑approved plumber in your area, visit: needaplumber.org
