Faulty Isolation Valve - No internal stopcock (Edinburgh Tenement)

[FootOfDavros]

Hi folks!

Just looking for a little piece of mind / advice here...

We live in a tenement flat in Edinburgh which has our central heating system in a cupboard in our kitchen. Every year I do a wee job of re-pressurising the expansion valve by running some flexible piping from a split point under our sink (unattaching the cold tap connection and attaching to the flexible piping).

Anyway, every time I do this I use a screwdriver to turn the isolation valve off / on as I am switching the connections over. Last night, once the job was done and the cold water reconnected, I went to turn the screw to open the valve and it started leaking / spraying water through the screw point! After screwing it in for a bit I eventually got it set to a position where the spraying stopped, so I mopped up the water, and checked again today and all fine, no signs of any leaking.

A couple of questions though -

1. Will this be ok? Will the valve be ok if it isn't leaking now, there's no reason for it to suddenly start leaking again?

2. I thought I'd buy some replacement isolation valves and replace both the cold and hot at the same time (in case that this was a sign of them ageing). BUT I can't find a stopcock anywhere in our flat! We live in an Edinburgh tenement and the pipe rises from under the concrete under our sink straight to this isolation valve. We have no water pipes coming into the flat from the stairwell (just gas & electricity) and no shut off point in our bathroom either. A neighbour advised me that there is a shut off in the street which will turn the entire block of flats supply off but this can't be right can it, i.e. that my only option to replace the valves would be shut off the entire supply?

Grateful for any advice, especially re the first question. Never had reason to think / worry about this before but quite scary if I have no quick means to stop the supply into the flat!

 

[steadyon]

1. Its possible that there is only the one stop valve for the entire block.
2. You could get a plumber to freeze the incoming pipe and replace the isolation valve. However:
2a. He / she would need 4 inches of clear pipe between the base of the isolation valve and the floor, otherwise it's doubtful if the freeze block would fit.
2b. I'd suggest replacing with a good quality 1/4 turn valve with a handle rather than a screwdriver slot. Pegler full bore lever valve or Pegler Tee ball valve.
3. Isolation valves have a ball inside them with a hole through it. Turning the handle / screwdriver slot turns the ball so that the hole lines up with the inlet and outlet or closes the inlet and outlet. The ball is usually nylon or similar, or rotates in a nylon or similar seating. If a bit of grit gets into the seating, water can come out where the handle is. You can sometimes (as you appear to have) turn the screw backwards and forwards until the grit goes, when the seal may or may not be remade.

 

[FootOfDavros]

Thanks for replying, much appreciated.

It's still ok now, so I guess like you say if there was grit there, the turning may have dislodged it (although when I was turning, there was only a very small point when it stopped spraying, so maybe just moved from the point it sealed).

I'll get one of the valves you suggested. Just for future reference (for a novice like me!) can I ask if there's anything I could / should have put right around where that screw was once I did get the spray stopped? e.g. if I'd dried and taped it with electrical tape does that make any odds or does the water pressure just make that a pointless exercise?

Cheers.

 

[oz-plumber]

Once the valve is leaking there is nothing you can do to repair it, bar replacing the valve.
You might have been lucky getting it to seal this time, I very much doubt you will be as lucky next time.

 

[Tim Watts]

Electrical tape will leak - it's just not that sticky. There are various plumbing tapes and putties that can be used, but they may be a tad permanent.

Me: I'd get a proper isolation valve put in (Pegler are good as said, I use these for main isolators) - at worst the plumber will just have to turn off the block for a short period, a note to the management agents or through everyone's door should be sufficient???

 

[Bogart]

Had same problem at daughter's flat. Could not find main isolation valve to the block. Ended up freezing the incomer and fitting a good isolation valve. A 90 degree ball valve is better than the normal stopcock/gate valve.