In this article, we’ll explain how to find your outside stopcock, including what it looks like and when you should use it.  

What you’ll need:  

• A torch 
• A flat head screwdriver
• External stopcock key (possibly needed)  

When do you need to use your outside stopcock? 

Your external stopcock should be used if you have a leak, you’re unable to find your internal stopcock, or if you have a burst pipe outside.  

It can also be used as an alternative to your internal stopcock before carrying out any plumbing work on your pipes or anything else that’s connected to the water supply, such as your toilet or sink.  

Find out how to cut the risk of internal flooding and water damage in your home with a Surestop Remote Stopcock installation from Dyno Plumbing.

Finding your external stopcock  

Your outside stopcock, often known as a stop valve, is connected to the main water pipe that supplies water to your home. This makes it easier to find, as its generally located on or near to the road outside of the front of your property. 

The search should start at the boundary of your home, either in the soil/grass at the very end of your garden or on the pavement/footpath that borders it.  

Tip: If you already know where your outside water meter is then that’s a great place to look for the external stopcock.  

What does your external stopcock look like?  

It will usually be covered by a metal or plastic lid and marked with a character such as “W”, “WM”, or a word, such as “Water” or “Stopcock”. The lid may also be covered by soil, grass, gravel or even a concrete slab. 

Having removed the cover, you’ll see a tap or key – this is your external stopcock. Turn this anti-clockwise to open and clockwise to close. About four turns in either direction should have the desired effect. Turn the valve carefully to prevent damaging it.  

If you still can’t find your external stopcock, it’s possible your home may not have one fitted. This is more likely if you live in a flat or an older terraced property.  

Important considerations before using your external stopcock  

Make sure you let members of your household know that they will be unable to use the water supply while the valve is turned off. This includes using everything from the shower and toilet to the washing machine and dishwasher.  

Also, let your neighbours know too, as often the water supply and external stopcock are shared between properties. If you live in a flat, then you may also need to contact your landlord or the owner of the building to get permission before interrupting the water supply.  

How do you use your external stopcock?  

You’ll need a flat head screwdriver to open the stopcock cover and access the valve. There may also be a protective frost pad inside that will need removing. At this point, a torch may be required to see the valve, even on a bright sunny day.  

In some cases, you may be able to turn the stopcock valve itself with the screwdriver. However, most of the time, a dedicated stop tap key is needed. You can pick one up relatively cheaply from a local DIY or hardware shop.  

To close the water supply, turn the stopcock valve in a clockwise motion. It’s likely that the valve will be quite stiff due to age and exposure to the elements. Usually, a combination of elbow grease and a lubricant such as WD-40 will do the trick.  

If you find that the stopcock won't budge, contact your local water supplier for help. Remember to let them know if you are dealing with an inside or outside flood so that they are aware it’s an emergency.  

Who’s responsible for the external stopcock?  

If the external stopcock is on or outside the boundary of your property, then the responsibility for repairs and replacement rests with your local water supplier.  

This is because your water company provides two piped services to your home. The delivery of fresh water, and the removal of sewage and drainage wastewater. 

This takes place via “supply pipes” that connect your home with the boundary of your property. And “communication pipes” that connect the boundary directly to the water main. 

Supply pipes fall within this boundary, which means if you have a burst pipe in your garden, it’s the responsibility of the landlord or homeowner to put it right. This also extends to external stopcocks that are found within the perimeter of the property.