How to Turn Off the Water in an Older London Home

Every plumbing emergency starts the same way: stop the water. Finding the stopcock in a hurry, in the dark, with water coming through the ceiling, is much harder than finding it on a quiet Sunday afternoon. Spend five minutes now and you will know exactly where to go.

Where to look

Thames Water says your internal stopcock is usually in one of three places: under the kitchen sink, behind the kitchen cupboards or under the stairs. In older houses in this part of London, it is worth checking a few more:

• Cellars and vaults. In Victorian houses, the supply often comes in at the front of the cellar, under the pavement side of the house.
• A cupboard by the front door. Common in houses converted into flats, where each flat was given its own supply.
• Behind a bath panel or in a utility room, where kitchens or bathrooms have been moved over the years.

If you live in a flat

In a converted house, each flat usually has its own stopcock, but not always. Some conversions still run every flat from one supply, and closing it cuts off your neighbours too. In mansion blocks and tower blocks, the valve for your flat may be inside the flat or in a communal cupboard or riser. If you do not know which, ask your managing agent now, not during a leak.

The outside stop valve

Outside the house, under a small metal or plastic cover in the pavement or front path, there is usually an outside stop valve. It belongs to the water company’s side of the supply and often needs a long key to turn. It is useful if the inside stopcock has seized, but it may also serve more than one property.

When the stopcock will not turn

Old stopcocks seize when they are left open for years. Do not hit it or force it with a wrench, because the spindle can snap off and leave you with no way to shut the water at all. Try the outside stop valve instead, and call us. We replace seized and leaking stopcocks, often with a lever valve that turns easily in an emergency.

While you are there: check for lead

The pipe that runs into your stopcock tells you something about your home. Thames Water says lead pipes are dull grey, have rounded, swollen joints, show shiny silver when scratched and make a dull thud when tapped. Homes built before 1970 may still have them. If you think you have found lead, ask us what replacing it would involve.

If water is already escaping, call 07862 142953 or WhatsApp us a photo. See also burst pipe repair.