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Seized stopcock

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AJW13/02/2021 18:35:56
337 forum posts
130 photos

Our incoming mains water supply is fitted with the original house build stopcock, soldered into the pipework it is immovable we still have a means of turning the supply off which works ok and is after the faulty one.

I would like to be able to use it and in the past have tried to introduce lubricant by removing the gland nut and applying blowlamp heat on the body, neither of which worked.

Access to the valve is not good as is just above the base of a kitchen cabinet otherwise I would consider freezing and removing the valve body for attention.

Anyone had a successful result in freeing a seized valve?


Steve Pavey13/02/2021 18:47:05
340 forum posts
39 photos

There should be a valve in the road or pavement outside which you can isolate the supply with.

I have freed off stuck valves before (usually gate valves which are notorious for seizing solid), but only by using the methods you describe - take off the gland nut and squirt plenty of penetrating oil down the shaft, then stick the handle back on and see if you can gently start it moving with some mole grips/water pump pliers or whatever tool you can find. I wouldn’t do this without locating a stop valve further upstream though - if it goes wrong it will ruin your day.

Les Jones 113/02/2021 18:47:55
2225 forum posts
153 photos

Before applying a lot of force I suggest buying or making a key for the outside stopcock so you can turn off the water in the event of something breaking.


noel shelley13/02/2021 18:52:07
486 forum posts
14 photos

I have the same issue and a second valve up stream. I would be very careful of touching it as if it goes badly you could land up in deep water and considerable expense. Is it the valve or the supply you intend to freeze ? If the supply then just have a spare BSP valve and instal it. If you have plastic pipe near by, be very careful using heat. Noel

Dave Halford13/02/2021 18:53:37
1395 forum posts
12 photos

That may well be why you have the second stop valve. Normally the loosening gland nut like you did works. If it's soldered onto a lead pipe I would just forget about it, you never know how much stick they have been given in the past and it could crack the pipe.


The secrete with both stop and gate valves is  never leave them turned on full hard just back it off a 1/4 turn so the thread is slack and it won't stick.

Edited By Dave Halford on 13/02/2021 18:59:13

AJW13/02/2021 18:59:34
337 forum posts
130 photos

Thanks for your replies.

Wise thoughts on being able to isolate the supply!

I have a long handled stopcock key that my Dad made but although it's probably three and a half feet long I couldn't even find the valve head with it - it's about 4 1/2 ft below pavement level and full of water! and no doubt silt.

Not sure of the size of the square, (3/4?)

If it's considered viable I will get hold of or make a suitable key, it's not been operated since I've lived here, 45 years.


Dave Halford13/02/2021 19:04:01
1395 forum posts
12 photos

Suspect it's different depending on Water Board but B'ham ones I have seen were a normal tee handle.

Andrew Tinsley13/02/2021 19:10:06
1343 forum posts

I had a similar problem with my next door neighbours supply. There isn't a water supply company stop cock!! His supply tap under the sink, wouldn't turn off, so he was in trouble when taps needed changing. I simply froze the old seized open stop cock and cut into the pipe above it and installed a second stop cock.

I can confirm that the freezing aerosols and insulated jackets work a treat. Gives you ample time to install a fresh stop cock.


Steve Neighbour13/02/2021 19:19:35
102 forum posts
1 photos

We live in the Severn Trent water co area, and had a similar issue with the stop cock under the sink, and also I couldn't access the main valve in the pavement as it was buried in mud.

I called STW to see if they could help (not expecting any help tbh) and was really surprised that not only did they send out an engineer the same day, who confirmed the main stop valve was duff.

They arranged to dig it up, replace with a new one all totally free !!

I could then easily turn off the supply and replace the one under the kitchen sink

So it may be worth contacting your own water company 🤔

not done it yet13/02/2021 19:33:18
5790 forum posts
20 photos

Let’s hope you are not on a water meter and the leak into your mains supply culvert, at the pavement valve, is your side of the meter! A friend had a supply to his property which was leaking a huge amount of water which was recorded before it was on his line. His office meter showed very little (normal) usage but his house supply was charged at about a hundred, or more, times the normal usage.

The water supply company admitted the wrong readings and fixed their leak. Sometimes, the water companies try to over-charge but are ‘found out’. My friend saved hundreds of pounds- and that was near 20 years ago.

I already knew my residential consumption (I fitted my own meter) before the water company contacted me re my request for a water meter, nearly 25 years ago. They forgot to mention that surface water drainage was charged on the metered supply (My property was served by a surface water soak-away, so metered water charges were reduced).

Using rainwater, for flushing the loo (whenever possible), will also considerably reduce metered supply charges as they charge 90% of the metered supply volume as a separate sewerage charge (as well as the reduced water meter readings).

Steviegtr13/02/2021 19:34:30
1976 forum posts
268 photos

When i replumbed my last house i needed to move the stop tap. As said above there is an isolation valve usually on the pavement outside the property boundary. I made a u shaped piece of flat bar & welded to a 2 foot bar to get down to it. A word of warning though , they can weep. I could not stop the flow completely & then it was awkward trying to resolder the tap back on.

When we had a plumber come round last year to fit a water meter. He went to the stop tap to turn off & i told him you will have trouble with that. I tried a few times to turn off unsuccesfully. He slackened the packing gland & used large plumbers pliers & undid it. I thought he would shear it off, but no problem. I would not have dared put so much leverage on the tap but i guess that i what he does regularly.


Simon Williams 313/02/2021 19:34:30
582 forum posts
80 photos

I hesitate to be the party pooper, but please take into account that introducing oil or penetrating oil into the public water supply (even if it is only your own individual supply) is illegal, and carries quite stiff penalties. It's not just jobsworth pedanticosity, even small quantities of hydrocarbons will taint your supply and you will taste them.

Materials in contact with drinking water must have passed through the Water Research Council approval program and be WRc approved.

There are food grade lubricants about - Rocol make one called Foodlube which can be bought in an toothpaste tube, but to the best of my knowledge it doesn't have WRc certification.

The materials used by the water companies have to be DWI (Drinking Water Inspectorate) approved, which is even more stringent to ensure that even small traces of deleterious substances are kept away from the public water supply.

Best answer by far is as suggested - get your local Water Supply Authority to check over their stopcock, so you or they can isolate your supply. Then remove and replace the offending consumer side valve.

You may have difficulty retaining command of whether a water meter is fitted or not, depending on the local policy.

Good luck!

alan-lloyd13/02/2021 19:39:13
173 forum posts

We had the same trouble with our stop cock, the plumber recommended leaving it alone and installing a Surestop valve just after it with the switch conveniently located under the sink unit at a height we could reach easily

AJW13/02/2021 19:58:14
337 forum posts
130 photos

Once again thanks for your replies.

The incoming mains is through copper pipe which is soldered into the stopcock, one close bend takes it to the water meter and then to another, working stopcock. All under the sink with the seized stopcock at plinth height. All very compact and located close to the wall at the back of the cabinet!

The valve did work 40 years ago and as you say was always backed off half a turn from fully on, it was also 'excersised' frequently to keep it moving but over the years it gradually got tighter.

I realise lubricant is not the thing to inject into a valve from a health point if view but I am sure there are many if us who would have tried similar?

So it's not in a 'must have working' situation but I would prefer to have it functional, as you have suggested it might be worth a call to the water company.


Oven Man13/02/2021 20:07:44
118 forum posts
8 photos

Seven Trent have recently changed our water meter for a new "smart" one. It has a battery that is expected to last about 12 years. It spends most of its time sleeping but wakes up when the meter reading van drives down the road and automatically loads up the reading. It does not have any facilities to switch off the supply remotely. Took the guy about 15 minutes to change it in the hole in the pavement. The new one is all plastic, the old one was all brass. Scrap value of the old one might just cover the cost of the new one. Makes the job look easy when you have the right spanners for the job.


J Hancock14/02/2021 14:36:19
558 forum posts

10 to 1 it is 'limescale' which is seizing your valve stem to the gland nut and anything else.

There are numerous household aerosols which claim to dissolve 'limescale', one ends in ' Bang ' , judicious use over many days would probably cure the problem.

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