How to Turn Off Your Water at the Stopcock
Locate your stopcock and shut off the mains water supply quickly to prevent flooding during a leak or repair.
Quick answer
Find the stopcock, usually under the kitchen sink or in a cupboard near the front wall. Turn the handle clockwise until it is firm. Run a cold tap to check the water has stopped.
Materials
- torch (optional)
- cloth or towel
If a pipe bursts or you need to change a tap washer, you must stop the water fast. The stopcock controls your home's mains supply. It is usually a brass or plastic tap with a small handle, found in a cupboard or under the sink.
Step by step
- 1
Find the stopcock
Check under the kitchen sink first. If it is not there, look in a downstairs cupboard, under the stairs, in the airing cupboard, or near the front boundary wall. It may be behind a removable panel. Use a torch if the space is dark.
- 2
Clear the area
Move cleaning products, boxes, or pipes out of the way so you can reach the handle. Place a towel on the floor to catch any drips.
- 3
Turn the handle clockwise
Grip the handle and turn it gently but firmly clockwise. Keep turning until you feel resistance. The tap should feel firm but not forced. If it will not budge, stop. Do not use a wrench or excessive force.
- 4
Check the water is off
Open a cold tap in the kitchen or bathroom. The flow should slow to a trickle and then stop. Leave the tap open to relieve pressure in the pipes while you work.
- 5
Turn it back on afterwards
When you have finished, close the open tap first. Then turn the stopcock anticlockwise until it is fully open. Open the tap briefly to confirm normal flow has returned.
If the stopcock is stuck, rusty, or starts leaking when you turn it, stop immediately. Do not use excessive force or tools. Call a plumber. If you cannot find the stopcock and have a serious leak, contact your water company's emergency line.
Common mistakes
- Forcing a seized stopcock and snapping the handle or valve body
- Turning off the outside stop tap, which belongs to the water company and may require their permission
- Forgetting to open a tap to release pressure before starting plumbing work
- Leaving the stopcock part-open, which restricts flow and can cause noise in the pipes
Frequently asked
What if I cannot find the stopcock?
Check under the kitchen sink, in a downstairs cupboard, under the stairs, or near the front wall. In flats, it may be in a communal area. Ask your landlord, managing agent, or water company if you still cannot locate it.
Why will my stopcock not turn?
Mineral deposits and lack of use can seize it. Try gentle, steady pressure. Do not force it. A plumber can free it safely or replace it with a modern lever valve that is easier to operate.
Should I test the stopcock regularly?
Yes. Turn it off and on once every few months. This keeps it free and lets you practise finding it in an emergency.
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