Where Is My Stopcock?

What is a stopcock?

A stopcock, sometimes referred to as a water mains tap, is a tap that controls the mains water supply coming into your house. 

You should really know where your stopcock is located in your home, just in case you need to turn your water off to do maintenance or if you have a plumbing emergency. 

What does a stopcock look like?

A stopcock looks like a tap but without a spout. It sits between two lengths of pipe, acting like a connector. This allows the stopcock to block the flow of water when it’s closed. 

Depending on your home, the stopcock will sometimes be coloured red, and it will usually either have a typical T-shaped handle, be wheel shaped or look like a lever. 

Do all homes have a stopcock?

All homes should have a stopcock, and it is a legal requirement to have at least one stopcock at your home either externally or internally. 

Does every house have an outside stopcock?

While every house should have a stopcock inside, it isn’t guaranteed that you’ll have one outside as well, especially if your property is old.

Types of stop taps

Your stopcock in your home will either be located internally or externally. 

Internal stopcocks 

Internal stopcocks can be tricky to locate, especially in properties which have been renovated as they often get moved or covered over. 

The most common place for a stopcock is under the sink, but if it’s not there, you should check:

• The airing cupboard
• The bathroom
• Cupboards under the stairs, and
• Utility cupboards. 

In older buildings, the stopcock may be located under the floorboards by the front door.

External stopcocks

External stopcocks are often located under a cover on the road or path outside the boundary of your property. 

If your house is older, or you share a supply with your neighbour, you might find it at the end of your road. 

If you’re on a shared supply, remember that turning off the stopcock will result in the water being turned off for everyone connected to that supply. 

How to locate your stopcock

Depending on the age of your property, you are likely to have two stopcocks. 

You will find one inside your home as close as possible to the point where the cold water supply enters your property. This is usually under the kitchen sink or in a downstairs bathroom. 

Where is my external water stopcock?

Your external stopcock will be located outside the boundary of your home, and it will be the responsibility of your water supplier to fix it if there’s a leak. 

The external stopcock will usually be marked by a metal cover, stamped with the word ‘stopcock’ or a ‘W’. 

Where is the stopcock in a flat?

If you live in a block of flats, your stopcock might be located in a communal corridor with the other flats stopcocks. 

If you have the plans for your property, the stopcock will usually be marked as ‘SC’. 

What to do if you can’t find your stopcock

If you can’t find your stopcock, it may be a good idea to ask your neighbour where theirs is, especially if you live in an older terraced house or flat. In older properties, they are often located in similar places, under the floorboards by the front door. 

If you’re still unsure, it might be a good idea to call your water supplier for assistance. 

In the case of a water emergency, it is vital you call professional help as soon as possible. If you can’t locate your stopcock, you can contact our emergency plumbers who will locate your stopcock and resolve the issue as quickly as possible. 

Issues that require a plumber can happen more than you think, and we understand the need for quick and effective fixes to prevent further problems. 

Why is it important to know where your stopcock is?

If your home has frozen pipes or a leak, you will need to turn off the water supply as soon as possible to minimise any damage. 

Any delay in turning off your stopcock can have a huge impact on your home if there is water entering your property. 

Stopcocks can seize up, leak or stop working, so it’s important to check yours is functioning properly and fix any issues before disaster strikes. 

How to fix a leaking stopcock

If you find a leak from your stopcock and you feel confident enough to fix it yourself, follow the steps below. 

Tighten the compression nut 

Once you’ve located where your stopcock is, check to see where the water is leaking from. If water appears to be leaking from the compression nuts, try tightening the nut on the body of the stopcock by using an adjustable wrench. 

Be careful not to overtighten the stopcock, as this will restrict your ability to open and close it. 

Replace the gland packing  

If tightening the compression nut fails to stop the leak, you’ll need to inspect and replace the gland packing. 

Before you start, it’s worth purchasing some packing glands from your local DIY store. To start, turn off the water supply and then locate and unscrew the gland nut. Once it’s done, you can remove the old packing with a sharp object. 

Insert the new packing, and then return the gland nut to its original position. Once you’re confident the gland nut is on tight, turn your water supply back on by opening the stopcock. 

If you have any questions or need help locating your stopcock, don’t wait until there is an emergency, get in touch with our friendly and professional team for help.