Stopcock no2 in kitchen turn off or keep on?

[BobbyJoe]

Hi everyone,

I have a query about two stopcocks in my kitchen. There is one under the sink which turns off the kitchen water, then I have a cold water feed gate valve in a cupboard near my bathroom which turns off the water in the bathroom.
However in the side of my kitchen wall there are copper pipes and I saw another stopcock, so I decided to run the cold water in the kitchen and bathroom then I turned on and off that 2nd stopcock and it doesn't seem to affect the water.

Should I turn that 2nd stopcock off as it doesn't seem to do anything as it may have been used when there was a water tank in the cupboard near the bathroom and perhaps had a lead pipe to it, is there any danger of just it leaving turned turned on?
Lastly if I turn it off then do I need to flush the water taps in the flat at all?

Extra info if it helps:

• Building Circa 1965 (approx)
• Pretty sure flat had lead pipes before council replaced them with copper
• Used to have water tank stored in cupboard near bathroom
• Used to have a hot water cylinder in cupboard near the bathroom
• I live on the top floor flat (2nd floor in a 6 in a block)
• Mains fed water throughout
• Gas combi boiler

Thank you for your time and any information or advice would be very much appreciated.

 

[Ric2013]

Well, if it goes to redundant pipework, then there may certainly be an advantage in turning it off in that it will reduce the length of the dead-leg of stagnant pipe that is connected to the mains.

The pipe may isolate something else, such as a communal service, but I suppose if you turn it off, sooner or later you will find out what purpose it serves by the fact that the management company may send a plumber to find out why there is no water supply to ***.

 

[BobbyJoe]

Thank you for the reply, I noticed that when I am in the kitchen whenever my downstairs neighbour turns her cold water tap in the kitchen I can hear a a knocking noise in my kitchen where the communal cold pipe runs, sounds like hammer head, what can I do about this?
Also the stagnant pipe looks like lead which I believe was used in its earlier day and as mentioned it doesn't serve any purpose there wouldn't be any chance of bacteria running through it if it were left open would there?

Thank you for any advice

 

[Ric2013]

Thank you for the reply, I noticed that when I am in the kitchen whenever my downstairs neighbour turns her cold water tap in the kitchen I can hear a a knocking noise in my kitchen where the communal cold pipe runs, sounds like hammer head, what can I do about this?

Realistically, water hammer is something that the best thing to do is get used to it, unless there is an obvious bit of loose pipe that can be prevented from vibrating. You can experiment with water hammer arrestors 'mini resters' or mini potable expansion vessels, but not really a DIY job as would involve cutting into pipes and even professionals often struggle with removing water hammer in this sort of circumstance.

Also the stagnant pipe looks like lead which I believe was used in its earlier day and as mentioned it doesn't serve any purpose there wouldn't be any chance of bacteria running through it if it were left open would there?

Thank you for any advice

If it's connected and the valve is open then the bacteria could breed in the stagnant section and eventually move into the pipes in use. In fairness, this probably doesn't cause a problem very often and many houses probably have this detail without anyone noticing. But, it might cause a problem which is why it is not legal to modify pipework in such a way that will result in this kind of dead leg.

 

[BobbyJoe]

Hi everyone,

The other day when I turned on the thermostatic shower no water came out, but every other faucet had water coming out except the shower. So the 2nd stopcock which does nothing has been turned off for two weeks, I turned it back on ran the shower which was started to work then turned the stopcock back off to check if that was the issue but no the shower has been working ever since although the shower water pressure isn't as strong as before but still enough.

My flat is mains fed, there are two water tanks in the attic in a building of 6 flats although I don't know the purpose of them because I have a gas combi boiler for dhw. I am trying to understand the pipe work in the flat, there are two pipes under my sink for hot and cold water with a stopcock which turns off the cold water in the kitchen. Then in the cupboard near the bathroom are two pipes one is hot and one is the cold water feed with a red gate valve which turns the cold water off in the bathroom only.
The hot water can only be turned off when I turn the isolation valve off on the pipe on the combi gas boiler.

Since I have turned the 2nd stopcock off there isn't any chance of a leak or anything is there and if I am mains fed then I wouldn't be connected to the tank in the attic? There has been a bit of knocking noise when I turn the kitchen tap off or on which wasn't there before but no pressure drop on my boiler or anything.

I would appreciate any advice thank you.

 

[BobbyJoe]

Hi everyone,

I figured out what the 2nd stopcock does in the kitchen wall. I ran the cold water tap in the kitchen and turned the stopcock on and off and what it did was control the water flow and even when fully turned off the water was still running albeit at a lesser rate than when fully open.

I am pretty sure it is an old stopcock but still functional, it is attached to a 15mm pipe which connects to another large pipe which runs down to the flats below me and supplies the mains drinking water to the other flats.

Are these 2nd stopcocks normal to have flats and should it be fully turned on?
Should there be a check valve or anything on the pipe to prevent any contamination or is it fine the way it is?

Thank you and any advice would be great.
Picture 1 is the stopcock under the sink
Picture 2,3 is the 2nd stopcock in the wall panel and to the right of the picture you can see the large pipe it is connected to which runs to the flats below me and may be the shared cold water supply mains pipe.

 

[rocketmanbkk]

Why is it on your mind?

Leave it alone

 

[BobbyJoe]

Thank you for the replies and the reason I am asking about both stopcocks are:
The 1st one under the sink is old more than 20 years should it be replaced as a precaution or can it last long?

The 2nd stopcock in the wall panel leaks when turned fully on which is why I have turned it all the way off then one turn anti-clockwise which runs the water but if I turn it any more the leak persists ( I have used tape, tightened the nut etc). This stopcock is also old and you can pics of them in the pictures provided.

I will replace the stop cocks any advice as the one in the wall panel which is the 1st picture is the mains water fed pipe stopcock which is leaking and the pipe to the right is the same pipe which is connected to the 2 flats below me as I live on the top floor as we all share the same mains fed water pipe in the kitchens.

Do I need to consider anything else such as check valves, Non return valve or anything else as the piping in the kitchen wall is over 20 years old.

Any advice or suggestions would be really appreciated thank you.

 

[Ric2013]

Sometimes you worry me. That isn't how you apply tape to a gland nut. It's called gland repacking and was shown in old DIY books before the stock answer to everything became to look it up on the internet. In principle I agree the leaky stopcock should be serviced or repaired, although in a hard water area you may find if you stick a bowl under it to catch the drips it will both seize up (bad) and stop leaking (good).

Stopcocks can be serviced, sometimes even if they are 50 years old or more and I was doing this long before becoming a plumber, but I started with old-fashioned rising spindle bath taps (which are functionally almost identical but less is at stake if it doesn't go to plan) before moving on to working on stopcocks. Not so easy to get the experience these days since people seem to be taking the motto "it doesn't matter if anything is any good so long as it is NEW" and those kind of old-fashioned taps are increasingly rare. In practice, even many plumbers may lack the patience (if not the skills) to carry out a full overhaul and it is not necessarily cost-effective.

20 years is not long for a plumbing fitting (I've taken out steel pipework that was 100 years old and still watertight and sound, so brass should last just as long if not longer) but depends on your water and the original quality of the materials. Bear in mind you probably have no insurance for the work you are proposing and home insurance may not cover if you are doing construction work, while a sudden failure may well be covered if you aren't fiddling with things.

As far as check valves etc. are concerned, when you have an old plumbing system, there will almost certainly be some ways that it does not fully comply with modern regulations. There is probably lead solder in the joints, both visible and underground. We'd hope whoever has done work will have worked with best practice in mind, but this is not always the case (even where work has been done by professionals, sadly). However, generally speaking I would not be replacing anything unless there is obvious signs of impending failure. Most of my house dates back to at least 2005, plumbing-wise, with some of the plumbing going back as far as the 1960s, and I have even reused some materials, where appropriate, when carrying out more recent modifications.

While I do commend you for your attitude in wanting to understand your home plumbing system, I really am concerned you may be at risk of doing more harm than good. It is very hard for me to understand exactly what your system is from descriptions over the internet, which is why I haven't commented further to your question above, though it seems possible some of your taps are fed from one stopcock and some from another (not quite in line with modern legislation but not necessarily a bad system to have). If you must proceed, make sure you have a way of shutting the water off quickly if something goes wrong on the section you have worked on. All the best.