Failed gate valve: how to stop hot water supply in flat?

[ianm]

Hi,
I need to replace the back nut on my hot bath tap. However, the gate valve on the cold water supply to the HWC seems to have failed and still allows a flow through the hot tap even when closed. I live in a flat, presumably with a shared cold water tank somewhere in the loft to which I don't have access. Is there any way I can stop the hot water supply to do this repair? Or failing that, is it a terrible idea to disconnect the pipe to the hot tap with the water still flowing slightly, quickly replace the back nut and reconnect the pipe?

Thanks,
Ian

 

[Simon F]

welcome to the forum.
do you know for sure that the nut will be able to quickly be changed??
the pipe could be frozen.
why do you need to change the back nut? can it not be tightened?
is there another hot tap that could be opened, possibly limiting the flow to the one you want to work on?

 

[ianm]

welcome to the forum.
do you know for sure that the nut will be able to quickly be changed??
the pipe could be frozen.
why do you need to change the back nut? can it not be tightened?
is there another hot tap that could be opened, possibly limiting the flow to the one you want to work on?

Hi Simon,
Thanks for the prompt response. The old nut was plastic and has split in two so definitely needs to be replaced. Opening the kitchen hot tap too sounds like a great idea. I'm assuming that if the pipe can be disconnected easily (haven't tried yet) it'll go back on easily too, and I just need a large enough bucket to hold the outflow for the time it takes to screw in the back nut.

Ian

 

[supper plumb]

is there now ISO valve on the pipe?
if the tha gate valve is bust then why not deal with that first by freezing then change the valve?


Sorry didn't read the post properly
its tank fed then bung the tank and crack on

 

[Dan Masey]

Bung the tank in the loft, change gate valve for a 22mm lever valve. Job done.

Failing that I'd be draining the tank personally and then fitting a new lever valve. Wouldn't chance doing it live.

 

[Gas]

This is easy, open other hot taps as suggested, fit a hose to an ISO and stick other end in bath/basin, cut through pipe quick as you can and throw the ISO on the pipe and tighten.

Even with a freely flowing gravity system you don't get that wet, nothing a couple of towels won't mop up.

 

[Bunker]

As above, but have loads of towels on standby just in case.
Shouldnt the landlord/ agents/ freeholder be sorting this? If you end up in trouble they might not be very sympathetic..

 

[Mike Jackson]

If there are other flats below you don't even think about trying to snatch it. Ground floor flat I'd think twice before doing it. If you can't get access to the cistern then it needs freezing to change the valve.

 

[Dannypipe]

Loads of options, freeze it, bung it, drain the tank.

Snatch has to be a last resort surely?

 

[Gas]

Loads of options, freeze it, bung it, drain the tank.

Snatch has to be a last resort surely?

Not when he has clearly said he has not got access to the tank and won't have a freeze machine else wouldn't be asking the question.

 

[Gas]

It is hardly a big deal on a partially shut valve anyway

 

[Leo21]

I've seen two piece back nuts just for this application, just can't remember where.

 

[Gas]

2 piece top hats?

 

[Mike Jackson]

Not when he has clearly said he has not got access to the tank and won't have a freeze machine else wouldn't be asking the question.

The flat below will be delighted when the snatch fails.

 

[Phil]

is there now ISO valve on the pipe?
if the tha gate valve is bust then why not deal with that first by freezing then change the valve?


Sorry didn't read the post properly
its tank fed then bung the tank and crack on

You still didn't read the thread properly supper.....he has no access to tank. :cool4:

Make sure you have a cold cylinder before trying a diy freeze in a hot airing cupboard.

 

[Dannypipe]

Well Gas, I would get access to the cold water storage. If he doesn't own a freeze machine cos he's a DIY'er do you really think it's a good idea to tell him to snatch a live fitting? Even partially closed, a gate valve will still pass a lot of water and if this guy doesn't know what to do, he could end up spending a lot more than it will cost him to hire a qualified plumber.

Infact that's my advice.... I've changed my mind. OP - I suggest you contact a local plumber.

 

[Gas]

Sorry, I am not going to treat the op like an idiot, he knows the gate valve is passing from cwsc, thus in the past month alone, knows more than a fair few plumbers arms members

 

[Dannypipe]

Fair enough. It's not your place, who cares.

If I was living below I wouldn't be best pleased. A litre of water on a ceiling makes a hell of a mess. I personally don't think amateurs should snatch live plumbing fittings.

 

[Gas]

Well Gas, I would get access to the cold water storage.

You do not have the right of access in most places, you would need to go through a services manager and not cut supply to other dwellings.

Read the original post next time, save a daft reply to correct yourself

 

[kay-jay]

Bung it. It is by far the easiest method

 

[Gas]

C'mon Danny, scaremongering does both nothing for our trade, makes us look right idiots.

 

[Dannypipe]

You do not have the right of access in most places, you would need to go through a services manager and not cut supply to other dwellings.

Read the original post next time, save a daft reply to correct yourself

You really think it's gonna be that hard to access the cwst? A call to the block management company is probably all that's required.

I didn't make a daft reply to correct myself. The best thing he should do is properly isolate the tap before he removes it. You don't seem to agree, but you think I'm the one talking crap.

 

[Dannypipe]

I'm not scaremongering? You know what, I'm done with this thread. If the DIYer messes up and damages the flat below, someone is going to have to pick up the bill.

Like I said, a single litre of water through a floor will come out in the flat beneath and at best mean the ceiling will need to be redecorated.

1st rule of plumbing. Isolation.

 

[Leo21]

2 piece top hats?

Two piece back nuts, designed just for this application.

 

[Gas]

We both know this is a cut job, we both knowthat is the best option. Anything else is bluster.


Good luck op, easy job, just get on with it and ignore the scaremongering

 

[Dotty]

Gas. The trusted advisors are that for a reason. Please don't accuse them of giving daft responses or scare mongering on a thread such as this.

The OP would be best to get a plumber in as advised. And snatching in this scenario is most certainly not to be advised.

 

[Killy Bing]

Use a local plumber, he can decide with the best route to take and in the event there is a leak it would be down to him and his insurances.

Hey gas, you might be local!

 

[ianm]

Hi,
OP here, thanks for all the replies. They were all very helpful and I can understand the different points of view. My feeling is that as a DIYer I most probably could manage to do the job, but just to guard against the small chance of something going horribly wrong I should this time get in a plumber and also get the faulty gate valve replaced, so that next time I CAN do it myself.

Cheers,
Ian

P.S. Some kind of hinged or two-piece back nut would indeed solve the problem, but my googling failed to find any such thing.

 

[Dannypipe]

The guys are talking about a top hat washer, a split type like this:SplitKlick - Home

But that's only useful if the backnut is still useable and not cracked.

 

[Dannypipe]

If you do want to buy some top hat washers, you can order them online here:
Split Klick Top Hat Washers Pack of 10 | NoLinkingToThis

 

[Bunker]

Ian, as you are obviously interested in achieving this (hats off for that), why not speak to whoever manages the freehold etc and find out how to access the tank - they really should facilitate that and you'll probably find your plumber might want to anyway.

 

[solutions]

Would this not be a perfect situation to use one of those new clamp on replacement lever valves? Would allow you to issolate the cold supply to the hot tank that the faulty gate cant. Golden rule of plumbing "isolation" fulfilled and work can comence with gusto.

 

[Mike Jackson]

It would if they were available in 22mm. As far as I'm aware they only make them in 15mm at present.

 

[Dotty]

It would if they were available in 22mm. As far as I'm aware they only make them in 15mm at present.

Beat me to it Mike.

 

[Leo21]

It would if they were available in 22mm. As far as I'm aware they only make them in 15mm at present.

Couldnt you snatch a 15 x 22 comp reducer in and then fit one?