Locating how mains supply is fed in to the house.

28 Jul 2012
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United Kingdom
Having switched the stop cock valve off which is in an internal cupboard in my house I replaced a tap washer and switched the stop cock back on. Initially all seemed fine but on opening the cupboard a couple of hours later I found the stop cock valve was leaking from a nut in the center of it. The valve has a red circular handle to turn the mains supply flow on and off and a brass nut in the middle. By turning the red handle to the left and the nut to the right I was able to reduce the rate of the leak but could not switch it off entirely. The leak is currently small but obviously shouldn't be there at all and I am reluctant to trust the stop cock valve in its current state.

I am a bit nervous about taking things further without knowing if I can shut off the supply to the stop cock from its source external to the house.

I live in a detached house, could someone please advise on how likely it will be that I will have a valve outside the house which feeds the internal mains stop cock and if so how I would locate it and whether I am allowed to switch it off or is that the domain of the water board/local council.

Thanks in advance
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how old is your house?

very often, the external stop cock will be just inside the house boundary, next to where the front gate used to be before it was moved, at the bottom of where the 18" pit used to be before it was paved over or filled in. Sometimes there is one under the pavement that has been tarmacced over.

If you look at similar houses down your road, there is a fair chance that one or more of them will still have it, and your will be in a similar position. You will probably have to dig it out and reinstate the pit.

The valve with a wheel head will be a gate valve, this is quite a handy sort of valve as it does not obstruct water flow when it is fully open, but it is not a proper watertight stop cock. Somebody probably fitted it when the old stop cock jammed, or they built a kitchen unit over it. The old internal stop cock might still be in your kitchen if you follow the pipe down.
Thanks for the response JohnD.

The house was built in 1924. After what you said I had a look at the pavement outside the house. Just to the right of our gate and slap bang in line with the middle of our house there is a small square metal man hole cover 6inches x 6 inches with a "W" on it I presume this it? Next to it there is a slightly bigger cover full of holes.

We only just moved in to the house a couple of weeks ago so are still finding our way.

I dont know much about plumbing so thanks for the information about the current stop cock valve type. The previous owner stated the one that is leaking is the main one for the house. It is located in a cupboard in a central hallway and is closer to the pavement outside with the small man hole cover than the kitchen which is at the back of the house.

I need to figure out how to get the small man hole cover off and have a look at whats in there. I will do a search.

Thanks again.
Picture might help, but a red circular handle usually indicates a gate valve, not a stop cock.
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the 6" square one is probably it. You might possibly have a meter under one of them. You will probably need an old spoon to scoop out the mud from the hole. Sometimes a very powerful hose will do it, but then you have to ladle out the water.

If there is no T-handle on the valve it probably has a square of some kind. You can get a long tool that goes down the hole and will grp differenty sizes of square plus a T handle. If it is very stiff wiggle it fractionally to and from a small amount at a time.

my tool
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I like to keep my pits very clean.
Gate valves are not designed for turning off water supplies from the mains.

However, I have found that new ones, even cheaper ones, do shut off mains in London very well and this has always surprised me.

The pressure here is only about 2 Bar though.

As they all say find stop cock ,if you do it may be seezed as well as its not been touched for 20 years but if not then your on your way .
If not if you have about 12inch of pipe you can get at freez it you put foam jackjet on it spray in a ozone busting chemical that evaperates off fast freezes the pipe make sure you have new stop cock or replace rubber if its **** or lead cut off & use a lead lock purchased from plumbers merch for £10 converts lead to coper , again you need a new stopcock if you do that ,but if its just rubber pull out clean replace ,I find stop cocks 25 y old are better replaced but others will disagree some are better than new ones (some times ), have fun not always stright forward .
Or call a plumber LOL

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