How to cut off hot and cold water

[Roger465]

OK… I really hate plumbing. It’s my Achilles Heel, so I prefer to let a professional do it. But, since I moved back to Ireland, I’m finding it impossible to get a plumber who will do small jobs so, very reluctantly, I’m considering learning how to do them myself.

The job I’m thinking of tackling now is replacement of various mixer taps etc, which are dripping – they’re about 25 years old, and all different, so I don’t think it’s going to be practical to replace the little ceramic whotsits in them or whatever. And even if I did that, I’m still going to have to figure out how to turn the hot and cold water off. I have 2 sinks, 2 hand basins, and the bath.

May sound simple, but not to me. Now, my very limited knowledge goes so far as to understand that both hot and cold water come from tanks (except the kitchen cold tap, which is on the cold riser).

So. I’ve looked in my airing cupboard, but there’s only one isolator tap (if that’s the right word) in there, near the bottom of the hot tank, and it doesn't stop hot water flowing from the hot taps. So I guess the isolator is either in the attic, or there isn't one, and you have to time the ballcocks up I the hot and cold header tanks in the attic, and drain them, to get the water to stop flowing, or there are going to be isolator taps up there?

Obviously I can go and look, and I will, but I recently had a foot of insulation laid, and moving around up there isn't going to be as easy as it was – I’d prefer to know what I’m looking for…

Thanks

 

[Iamchamps]

Is there no isolation valve on each pipe probably a foot or so from the taps? Under sink etc

 

[Roger465]

Is there no isolation valve on each pipe probably a foot or so from the taps? Under sink etc

Hah! You must be joking

Sorry though, should have said - I want to tackle that job first - once I find out how to cut the water off

 

[Notch7]

The most basic way to cut off water completely is to turn off incoming mains stopcock.

Once youve done that, turn on cold water taps / flush cisterns.

Dont forget some cold taps maybe mains fed.

When the water stops flowing, turn on hot water tap -not much will come out as hot tank cant empty if it cant refill.

I would guess what you call the hot water header tank, is central heating

 

[Roger465]

The most basic way to cut off water completely is to turn off incoming mains stopcock.

Once youve done that, turn on cold water taps / flush cisterns.

Right, gotcha

Dont forget some cold taps maybe mains fed.

Yes, that I do know – but only the kitchen sink one as far as I can tell.

When the water stops flowing, turn on hot water tap -not much will come out as hot tank cant empty if it cant refill.

I would guess what you call the hot water header tank, is central heating

Ah OK, so the hot tank fills from the mains, does it… yes, of course, see what you mean about the hot header tank – thanks

 

[winston1]

The most basic way to cut off water completely is to turn off incoming mains stopcock.

Once youve done that, turn on cold water taps / flush cisterns.

Dont forget some cold taps maybe mains fed.

When the water stops flowing, turn on hot water tap -not much will come out as hot tank cant empty if it cant refill.

I would guess what you call the hot water header tank, is central heating

That will work but unnecessary. The most common place for isolation valves is on the output pipes from the cold tank in the loft. Turn then both off. Simples. To work on the kitchen tap also turn off the main stopcock.

 

[lostinthelight]

If you have a vented hot water cylinder in airing cupboard then it should be fed at the bottom via a 22mm pipe from the large cold water tank in the loft. This tank is fed from the mains and not the hot water cylinder.

 

[dilalio]

Ah OK, so the hot tank fills from the mains,

Nope. You misunderstood.

The cold water storage cistern (big tank in loft aka CWSC), on a standard gravity-fed system, supplies cold water to the cold water taps and wc cisterns AND ALSO cold water to the hot water cylinder (hot tank as you call it aka HWC), where it gets stored and heated, indirectly, via the inner coil and then supplies the hot taps. When a Hot tap is opened, the head (weight) of cold water in the CWSC wants to drop under gravity and pushes hot water out of the HWC top connection and onto the hot tap that is open.

If you isolate the rising main and drain the CWSC via the cold taps (opening them all speeds the process). Then there will be no head (volume) of water left in the CWSC to push water out of the hot taps and all you will lose is what's in the pipework - this way you won't waste any hot water. If the isolation valve on the feed to the HWC works, you can also turn that off to stop any water from the CWSC entering the HWC - this will help reduce the risk of air locks when refilling the CWSC.

If your loft is hard to access and you are unsure if there are even any isolation valves there, this is the simplest way to proceed.

 

[Roger465]

Thanks, that's very helpful. Of course, playing around last night, I discovered that the main stopcock under he kitchen sink doesn't even work - ie you turn it fully off, and the cold water tap continues to flow as if you'd done nothing. And it's definitely connected directly to it

Maybe I'm just going to have to try offering greater and greater sums of money to local plumbers until I manage to tempt one into activity. What got all this going is this: My cousin in Somerset got (I think) a cracked toilet cistern when he was away, and came back to a flooded house. Now, isolator valves aren’t going to help with that – but what I’m thinking about is, if I’m doing some work in the house, and accidentally break (or even loosen) a little pipe under a sink or whatever, and can’t turn the water off, I face the same scenario.

So I guess what I want is a new main stopcock, and little isolators under all taps (and the toilet cisterns) – and maybe flexible pipes from them to the sink taps etc, then maybe even I could manage to replace worn taps etc when I can afford to.

I suppose, in the meantime, I’ll brave the attic and see if I can find the outlet from the CWSC, and hopefully an isolation tap there, which will enable me to cut the water off in an emergency. But replacing the main stopcock isn't something I feel I should tackle, so like I say, maybe just try harder to get a plumber

Thanks for all the helpful info though everybody – at least I have some understanding now

 

[lostinthelight]

If you have room and while the tank is drained it may be worth fitting full bore isolation taps on the tank outlets, usefull if you have a burst in the loft, or insde the airing cupboard , quick to turn off for maintenance.
Make sure any replacement taps and fleible pipes are suitable for low pressure or youll only get a dribble from them .

 

[Roger465]

If you have room and while the tank is drained it may be worth fitting full bore isolation taps on the tank outlets, usefull if you have a burst in the loft, or insde the airing cupboard , quick to turn off for maintenance.

First time I looked into all this, I had a plumber coming round to do just that – of course he never turned up.

Make sure any replacement taps and fleible pipes are suitable for low pressure or youll only get a dribble from them.

OK thanks

 

[dilalio]

Are you on a water meter? Look for the suppliers stopcock outside your property.
If it's been metered usually that means it should be a new, easy to operate, lever that will enable you to isolate your supply. You could then change your internal one for a lever valve and then proceed with other plumbing works required.

 

[Roger465]

Are you on a water meter? Look for the suppliers stopcock outside your property.
If it's been metered usually that means it should be a new, easy to operate, lever that will enable you to isolate your supply. You could then change your internal one for a lever valve and then proceed with other plumbing works required.

No - we have so much water in N Ireland we don't even have to pay for it at all

 

[Madrab]

Lets do this in easy stages ....

First .... if the internal mains stop tap doesn't work then you'll have to go outside and find your mains stop tap (or phone you water company and ask them to come out and check it isn't seized). That then allows the internal one to be changed. Once that's all done then report back

 

[dilalio]

No - we have so much water in N Ireland we don't even have to pay for it at all

Unless it's 3" deep in your lounge