Where to look
Your stopcock, also called the inside stop valve or stop tap, is usually where the water pipe comes into your home. Check these places first:
- Under the kitchen sink. This is the most common place.
- In the airing cupboard.
- Under the stairs.
- Near the front door, or under the floorboards just inside it.
- In a garage, utility room, bathroom or cellar.
In a flat, also check the cupboards by your front door and in the hallway. If you still can’t find it, ask your landlord or managing agent.
How to turn it off
- Turn the handle clockwise until it stops.
- Open the cold tap in the kitchen. When the water stops running, it’s off.
- To turn the water back on, turn the handle anticlockwise, slowly.
Don’t force it. If it’s stiff or won’t turn, leave it and call a plumber, because a valve that’s forced can break.
Check it works
Thames Water suggests checking your stopcock once a month: turn it off, check the water stops, then turn it back on. That way you know it works when you need it.
Tie a label on it, so everyone in your home can find it in a hurry.
Whose job is it?
The inside stop valve is part of your home’s plumbing, so keeping it working is up to you. If yours is stiff, leaking or hard to reach, we can fit a new one.
Source: Thames Water, find and use your inside stop valve (checked October 2026).