Plumbing question re bath taps (it'll end in tears no doubt)

[fuzzy]

Dear collected Guru's of this parish. I have been given a mission and seek your sage advice and the benefit of your experiences (positive and negative).

SWMBO wants to change the taps in the bathroom. On the wash basin this will be easy enough as the pipewrok is fitted with in line isolator valves.

Having explored the dusty, cobweb and associated beastie filled depths behind the bath panel however, I can see that the pipe work does not have the isolator valves.

My question is this-

To prevent a flodd of biblical proportions (or any proportions at all for that matter), what do I do to cut off the hot water flow?

I know that I can cut off the cold water flow by stuffing a wine bottle cork in the feed pipe in the header tank in the loft and I suspect that I cut off the hot water flow by turning one of the two or three stop cocks in the cupboard conatining the hot water tank. These stop cocks however are offering somewhat resolute resistance to any attempt to turn them. I can have at the stop cocks with various fettling tools such as spanners, mole grips, stilsons and hammers but I reckon this will defeat the object of this thread and result in a biblical flood at least (when my ham fisted fettilng breaks something).

I seem to remember that if I cut off the cold water supply to the hot tank, this in turn cuts off the hot water flow. If this is the case, should my loft mounted header tank have a seperate supply to the hot water tank into which I can insert another wine bottle cork. I hope this is the workable solution as it reduces the liklihood of me breaking something and gives me an excuse to open another bottle of wine.

I WILL be installing in line isolator valves under the bath when I change the taps

Thanks in anticipation.

Luv n' Stuff.

Fuzzy

[mrcharly-YHT]

you can turn off heating/hot water, cut off cold water supply, then turn on the tap in the bathroom, wait until water stops flowing.

Or

Turn off stopcocks at cylinder as you've mentioned (DO check you are trying to turn them the right way), then drain pipes by turning on tap.

[urban_biker]

If you can isolate the hot tank then the second option is better if you can do it as it saves you losing a tank of hot water down the drain. But if there is no other option then just shut of the mains water and drain both hot and cold systems by the taps

[hairyhippy]

If stuff is seized, get a plumber.

[hbunnet]

Yes, plug mains feed and drain the lot.  Then fit in line isolators for the next time.

It is also possible to get a kit to freeze the pipes while you do a quick job.  I did this several years ago to avoid draining the heating system while fiitting an extra radiator.

It's a jacket secured with cable ties and and refrigerant in an aerosol.   Bought from a DIY shed. 

[Feanor]

If you can isolate the hot tank then the second option is better if you can do it as it saves you losing a tank of hot water down the drain. But if there is no other option then just shut of the mains water and drain both hot and cold systems by the taps

If you can shut off the cold inlet to the bottom of the hot water cylinder, then you will not lose the contents of the cylinder when you open the tap; just the contents of some of the pipework.   Remember the hot water is taken from the top of the cylinder, and without pressure coming in the cold feed, there's nothing to push it up and out the exit pipe at the top.

THis can be done either with a a set of rubber bungs, or at the isolation valve at the cylinder.

If using bungs, get a set of 2 and bung both the feed down to the cyclinder at the bottom of the header tank, and also the expansion vent which will be dangling over the top of the tank.   This will vacuum-lock the hot water pipework so you spill less that the entire pipe-load when you open the tap.

[nicknack]

If stuff is seized, get a plumber.

Definitely.

BTDTGTTS

[vorsprung]

With our boiler, if you shut off the water supply to it then it doesn't "fire" and it doesn't supply any hot water.

So shutting off the hot water supply to the boiler effectively means that nothing comes out of the taps.  So you can change the taps without any leakage.

Probably not all (many) boilers work like this but ours does

[Kim]

Fit some in-line isolating valves while you're at it.  You can get them integrated into flexible hose thingies that connect to the bottom of the taps, which makes all the fiddly bastard knuckle-skinning aspects of the plumbing job easier, while guaranteeing that you'll never^[1] have to so much as change a washer in the new taps.



_{[1] The law of sod dictates that plumbing failures occur on annoying things like seized hot water stopcocks, rather than easily accessible taps fitted with in-line isolator valves.}

[tonycollinet]

If you can't close any of the appropriate valves, tie the float valve in the header tank up, so that it shuts of the water feed that way.

[Paul]

I suspect that I cut off the hot water flow by turning one of the two or three stop cocks in the cupboard conatining the hot water tank. These stop cocks however are offering somewhat resolute resistance to any attempt to turn them. I can have at the stop cocks with various fettling tools...

I'm not sure that these stop cocks are stop cocks, or that they are the things you need to be able to turn in order to stop the supply, but just in case it's a VERY EASY SOLUTION TO EVERYTHING, why not try a bit of wd40 + patience on them first?

[Palinurus]

If stuff is seized, get a plumber.

But don't pay cash.

[hairyhippy]

If stuff is seized, get a plumber.

But don't pay cash.

and make sure that you pick up the correct business card from the local phone box.

[fuzzy]

I love this place

I now have the info I need and have been given the confidence to gird my loins and get on with it.

Thanks folks

[rogerzilla]

The easiest way is to tie up the ball valve in the loft cistern and then run the bath cold tap until it stops.  Then turn on the bath hot tap and it will hardly run at all until it too stops.

This assumes both taps are fed from the cistern, obviously.

An alternative (quicker) way is to block the exit pipes from the cistern with a cork or similar, to avoid draining the tank at all.

Instead of tying up the ball valve, you can turn off the mains but (unless you have a working stop tap for the cistern alone) this means no water anywhere else in the house.

The low pressure stop taps (gate valves) with a red circular handle never work.  Forget them.

[David Martin]

The other tip is that when you open a stopcock, open it fully then back off about 1/4-1/2 turn. That way you know whether it is seized or not when you come to turn it. And it is good practice to turn them a half turn either way every so often to stop them seizing.

[Ashaman42]

why not try a bit of wd40 + patience on them first?

Take care with this. I believe that WD40 is among the list of lubes that does bad things to the rubber seals in stop cocks.

I think duck oil is what my grandad said to buy/use but can't remember for sure.