How to turn off upstairs cold water to bath

3 Feb 2014
Reaction score
United Kingdom
I realise this is a pretty dumb question, but how do I turn off the cold water supply to the bath (upstairs bathroom)?

As far as I can see the tank in the loft feeds the hot water, the shower pump, and also cold water to the upstairs basin and bath in the bathroom and the downstairs cloakroom.

(Upstairs and downstairs toilets are fed from the main along with kitchen cold water and appliances).

I have a broken bath filler tap that needs to be replaced. I have contacted a plumber but would also like to know how to turn off the supply to that tap if necessary.

Query: My loft tank has 6 pipes connected: (pics attached)

Pipes 1 and 2 at the top - the inflow pipe and the overflow.

Pipe 3 in the middle - another pipe connected at the side of the tank with a tap (gate valve?) on it. I don't know what this is.

At the bottom: 3 pipes connected. Two with taps one without. I think the two with taps are (a) for the hot water and (b) (with a red circular tap handle) the feed for the shower pump. I once had to temporarily turn water off in the kitchen downstairs and did this by turning off the main stop cock downstairs and all the taps coming out of the loft but have never turned off cold water to the bath upstairs.

I've looked under the bathroom sink and taken the bath side panel off. There's a pretty good view of the pipes there and I can't see any isolation valves on the pipes.

Could it be that the cold supply for upstairs is the pipe without the tap? Does this mean that to turn it off I would have to turn off the main stopcock downstairs and drain the tank completely ? That seems a bit odd.

Sorry for long post, any advice much appreciated. I attach pics of the pipes on the tank


  • DIYforum1 bottom pipes.jpg
    DIYforum1 bottom pipes.jpg
    248 KB · Views: 1,225
  • DIYforum2 middle pipe.jpg
    DIYforum2 middle pipe.jpg
    232.8 KB · Views: 1,183
  • DIYforum3 upper pipes.jpg
    DIYforum3 upper pipes.jpg
    188.6 KB · Views: 1,196
  • DIYforum4 taps.jpg
    DIYforum4 taps.jpg
    223 KB · Views: 1,251
Sponsored Links
I'd suggest that:

1. The very top pipe (picture 3) is the inlet to the cold water storage cistern (CWSC).
2. The white plastic "middle" pipe (pictures 2 and 3) is the overflow.
3. The three pipes coming out of the base of the tank will be the cold water supply to various places. One will be for the hot water cylinder,(HWC) one the cold water supply generally, and at a guess the third will be for a shower.

If the shower was fitted after all other cold water outlets, its most likely (no guarantee) the grey plastic pipe on the right of your pictures. This would suggest the other two are the HWC feed and the cold water supply.

Try turning both valves off and see if this stops the flow of water to the bath. If it does, turn one on, and if the bath hot water flows again, that's the cold supply. Otherwise, its the other one. Turn both valves on again once you've finished.
and don't turn them fully on

It's always better to leave a bit of room so you can rotate in both directions. That way if it is stiff when you need it in a rush, you can open the valve slightly then close it
As Old buffer says - plus go for the stopcock first, try that then the red head gatevalve. For some reason people fit stopcocks on low pressure cold down services. And gatevalves can break shut.
Sponsored Links
Sincere apologies for not having acknowledged these helpful replies sooner. What happened was I thought I'd used my main email address as the contact for this forum whereas I'd used the 'other' one and didn't spot the reply alert when it arrived (have had a lot of other stuff going on). Anyway, many thanks for the explanations and advice especially OldBuffer that clarifies things a lot.

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local