Quick answer
The internal stopcock is usually near where the mains water pipe enters your home, often under the kitchen sink, in a cupboard or by the front door. Knowing its location before a leak happens can help you limit damage.
Common places to look
Start where the incoming cold-water pipe enters the property. In many houses, the valve is under the kitchen sink, but it may be in a utility room, airing cupboard, basement, garage or near the front door. Older properties can have a stopcock beneath floorboards or behind an access panel.
Look for a brass valve with a round wheel or a lever handle on the pipe. Do not confuse it with a small isolation valve serving just one tap or appliance.
Check it safely
- 1Ask household members or your landlord where the valve is, and check any property handover notes.
- 2Clear the area and identify the valve without disturbing pipework or stored items that could fall.
- 3If it turns easily, close it gently clockwise, then check a cold tap. Reopen it gently by turning anticlockwise.
- 4If it is stiff, corroded or leaking, stop. Do not use tools or apply force.
If it is not inside
Many homes also have an outside stop tap, often in a pavement or boundary box near the property. It may be shared or operated by the water company, and access can require a key. Do not lift heavy covers or interfere with a shared supply. Contact your water company or a plumber for guidance.
A homeowner is generally responsible for the supply pipe from the boundary or external stopcock to the home; the water company is generally responsible for the network before that point. Confirm the arrangement with your water company, particularly for shared or unusual supplies.
When to call a plumber
- You cannot find a shut-off valve and need one identified.
- The valve is seized, damaged or leaking around its spindle.
- Water continues flowing after the internal valve is closed.
- You suspect a leak on the incoming supply pipe.
Common questions
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