If you have a serious water leak in your house, you may need to shut off your water source using the stopcock.

The stopcock controls the water coming into the house from the main water supply so in most cases it will stop the leak, but it will also block the water supply to the entire house.

Shutting the stopcock however may not fix the leak if:

• The leak is coming from your neighbour’s property
• The leak is because of ground water coming from a drain (perhaps after heavy rain)
• If you have a hot or cold water tank that the leaky pipe is being fed by, the entire tank must drain before the leak will stop

If you turn off the stopcock it is usually also a good idea to turn off your boiler to stop the boiler running dry and getting damaged (although most modern boilers will detect if there is a problem with their water supply).

Before you turn off the stopcock it is a good idea to check if there are any other isolation valves on the pipework you are trying to turn off the water to. Using these valves means you don’t have to turn off the water to the entire house.

Need help finding your Stopcock?

In most houses the stopcock is located under the kitchen sink. To turn off the stopcock simply turn the valve clockwise to turn off the water supply.

In some houses there may also be a stopcock outside the house – look for a metal plate with the words “Water” or sometimes just a “W” on it.

Once you have lifted the lid turn the valve clockwise to turn off the water supply. Note that in some cases you will need a special long tool to reach the stopcock. This is available from any plumber’s merchant or DIY store. Be careful turning off the external stopcock since if this stopcock is not in your grounds it may also be serving other homes.

When turning stopcocks back on it is a good idea not to turn them on fully to prevent them from getting stuck in the future. When turning on, turn the valve anti-clockwise as far as it will go and then give them a 1/8th of a turn clockwise.

If you are struggling to find your stopcock or have found it and it is stuck, you may need professional help. Use our site to find a plumber to help fix your problem.