water turned off but still dribbling out of pipes

[foy9999]

Hi there.

I'm fitting a mixer-tap where there used to be 2 separate taps and had to turn off the hot and cold to do this as there are no isolation valves in the pipework.

house is split-level. Boiler is not combi.

Turned the stopcock off in kitchen and cold in kitchen stopped running but no chance to the cold (or hot) in room I'm working on which in in lower lever.

A friendly kitchen-fitter came went up loft, said he closed off 5 things (don't know if they were gate-valves or stopcocks) and bot the hot and cold in lower-level now 'off'

However there was still enough water coming out the pipes to get the floor pretty wet so I put the old tap unit back on the pipes to keep things dry as the floor-fitter wanted to get the laminate down.

When he was done I could still fill a couple of cans with water from the tap before the dribble turned into a very small dribble.

I could then quickly cut the pipes and put isolation-valves on but still too much water for my liking and it all needs to be disturbed again tomorrow when the worktop etc is offered up.

Is it the case that gate-valves don't completely shut off the supply from tank?

Saw a video on YouTube where the guy said stopcocks do but water will get past gate-valves.

Or has the guy just not closed them tightly enough?

Or is this just water in the pipes coming down under its own pressure (gravity)?

 

[gaz1]

a shut off stop cock dosnt always mean its off if its failed

as goes for tank always open upstairs taps and flush that toilet plumbers dirty tricks is flush the toilet while your working on the pipe more so when youve cut the pipe

gate valves mostly do work when there off but wear or dirt in them takes a few opening and shutting them for them to shut closed properly

some mixer taps can back flow when open but the newer ones arnt supposed to do this anymore

 

[voipio]

Opening several taps usually helps, but there's often still enough water left in the pipework to occasionally spoil the party when soldering joints. If there's an expansion tank or an air gap in the top of the cylinder cylinder, these can force a good few litres of water through the system before it stops running. A wet vac can be used on an opened joint/cut pipe to try and get all the water out. Keep a container handy, and an old towel, to catch occasional drips.

 

[pedrobedro]

I have to turn our supply of at the street as the stop cock doesn't seal well and I can't be bothered to dig it out and repair it. Gate valves usually work on non pressurised systems not at mains pressure. Opening the upstairs taps lets any residual water drain out quicker I find though I am not a plumber just an interested bystander.

 

[foy9999]

thanks for the tips guys. I'll report back tomorrow. Am thinking it might be worth going into the loft before I start and checking all the 'closed' valves. mb just need nipped up a bit tighter

 

[Pigeon_Droppings2]

More than once I've stuck a carrot(s) in the cold feed(s) (from within the tank) and the vent pipe from the hot water cylinder that goes into the cold tank...creates an airlock that can be enough to get away with.

 

[JMS1972]

A rubble sack is quite a good way to catch water when plumbing.

It can get into all sorts of places you can't get a bucket.

Learnt this from an old plumber. Thought I'd share as I hate plumbing jobs

 

[Kayos]

Something not shut right, 5 valves in the loft sounds like he's turned off unrelated stuff

If you have access then a couple of high quality, full bore isolators will stop the water while you work

 

[foy9999]

I'm on my way to Screwfix for a few bits but think I'll pop to greengrocers too - far a carrot. Top Tip

 

[Alan Reynolds]

More than once I've stuck a carrot(s) in the cold feed(s) (from within the tank) and the vent pipe from the hot water cylinder that goes into the cold tank...creates an airlock that can be enough to get away with.

That’s a top tip. I had to replace the jammed isolating valves on the loft tank with over 500 litres of water still in it and didn’t want to drain it. It works!

 

[Bravheart]

Stopcock will only do kitchen cold and stop tanks filling you need to stop outlets from the tanks for any other room.

Cut pipe quickly and fit isolator ASAP shouldn't be too big a puddle if only a drip anyways.

 

[mart]

In place of gate valves, I fitted lever ball valves. Well worth the extra money. Turn them on/off in less than two seconds. I don't know what the intended use is, but they work great for water.

 

[bricol]

I have to turn our supply of at the street as the stop cock doesn't seal well and I can't be bothered to dig it out and repair it. Gate valves usually work on non pressurised systems not at mains pressure. Opening the upstairs taps lets any residual water drain out quicker I find though I am not a plumber just an interested bystander.

A gate valve in working condition will certainly stop mains water pressure! A standard-ish rating is at least 16 Bar.

 

[bricol]

Cheap pipe freezing kit has helped me a lot - although the first time I used it on the incoming mains was a little nerve wracking!

Stop cock in the street, when I finally found it and dug it out, had no effect - and no neighbours complained of no water . . .

 

[brewdexta]

In my first house, the mains water was fed through a lead pipe that I had to sweat a copper pipe into. This was before lead piping was a no-no. Turning off the main stopcock in the driveway didn't completely stop the flow, a trickle was still coming through, sufficient to stop me soldering the pipe. I was scratching my head on how to do this when my plumbing mate dropped by. He asked me if I had a loaf. He took the crust and shoved it down the lead pipe, rammed it in bit by bit until it was nice and tight then soldered the copper pipe on no bother. The bread dissolved in the water after a few minutes and was washed out when we turned the stop cock back on

 

[Dee J]

More than once I've stuck a carrot(s) in the cold feed(s) (from within the tank) and the vent pipe from the hot water cylinder that goes into the cold tank...creates an airlock that can be enough to get away with.

Tried that once in younger and more naive times. The hot tank started to collapse with the negative pressure generated....

 

[pedrobedro]

Cheap pipe freezing kit has helped me a lot - although the first time I used it on the incoming mains was a little nerve wracking!

Stop cock in the street, when I finally found it and dug it out, had no effect - and no neighbours complained of no water . . .

I had the water board out to ours when it wouldn't turn off, they were there to fix it within the hour. Our houses all have individual supply and stop as per regulations.

 

[foy9999]

In place of gate valves, I fitted lever ball valves. Well worth the extra money. Turn them on/off in less than two seconds. I don't know what the intended use is, but they work great for water.

yeah I wondered about that. I've fitted on e before but not sure why there are so many types. I guess the benefit (as you say) is speed of use

 

[foy9999]

anyway fwiw the job is done and no more leaks. I turned the water back on and he'd basically tuned off 2 gate valves leading into the cold tank; 2 coming out (1 went to shower pump) and one to the cold water (I think); there was also a stopcock which was in a pipe which seemed to wander off in direction of garage.

Still not sure how the hot and cold went off unless the one I assumed was for cold tee-d off to the boiler

 

[mtt.tr]

More than once I've stuck a carrot(s) in the cold feed(s) (from within the tank) and the vent pipe from the hot water cylinder that goes into the cold tank...creates an airlock that can be enough to get away with.

This is genius