cold tap in bath and cold (mixer shower) not working

10 Feb 2007
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United Kingdom
Hi all,

firstly you have no idea how helpful this whole forum is, only wish i could offer advice (only specialised subject is audio visual)

here we go again another plea for help.

I have a bathroom with a basin ( hot and cold)
a bath (hot and cold)
a mixer shower above the bath

i have noticed that the cold tap on the bath was getting stiffer and the water was not outputting very good pressure. the basin cold supply was fine.

now the cold water from the bath has stopped altogether and the shower is only outputting hot.

the cold from the basin is still fine.

on looking through the forum i have concluded that the cold pipe is blocked. Is there a way to check this?

Is there anything else it could be?

anything information would be gratefully received

thank you in advance

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I think that a blocked cold supply pipe is unlikely - more usual is that the body of the tap - or maybe just the washer itself - has stuck down. Remove the tap insert (water off naturally) and have a good look at it. If there isn't any washer visible it will have lodged in the tap unit somewhere. New tap inserts are available (B&Q etc) but there are several types so its best to take the old one with you. When you screw the insert back in, make sure its in the open position, then close it off before you turn the water back on. Cheers John :)
Thanks for the speedy reply

I can see how that would affect the tap but would that have an affect on the shower (may not have made myself clear) as that has its own control(ie flow and temprature) which is seperate and not acched to the taps

OK sorry I misunderstood the original post, and thought that the shower was part of the mixer tap and had its own switch over.
A the basin and bath fed from the same cold supply? For example, the basin may be mains water but the bath could well be tank fed from the loft - but not if you have a combi boiler!
So, the basin is OK but the bath / shower have limited or no cold feed. I don't see how a stiff bath tap can affect the shower as there seems to be no connection. So, I have to conclude that you do have a blocked pipe unless you have some sort of strange tank arrangement in the loft! I've just seen one system that had one loft tank to feed the copper cylinder, and one more to feed the domestic cold supply...... Good luck! Cheers John :)
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Thanks for that john

we do not have a combi boiler and do have a water tank in the loft.
one more thing to add is that we have two bathrooms( next to each other) and the second one is fine. So i guess the problem is local

any ideas of what checks i can do before i call a plumber in.

I am thinking that a check on the pipes leading to the tap and shower but am totally lost after that

Sometimes the shower had its own cold, supplied from a storage tank in the loft. Standard tank with floating ball cock. This same supply may have been used for the bath cold supply, in which case the supply to the shower and bath is blocked. I suspect if this is the case sediment has got in from the tank. Try back flushing the cold supply at the bath., pushing it back to the tank, Or, forcing water from the tank down to the bath (tap open).
Or the ball cock has stuck and not filling tank!
Thanks for that

i am presuming that the tank must be ok as if it feed one bath/shower surely it must feed the other as they are next to each other,
i am guessing that it must be the pipe.

are the above methods easy to do or should i get a plumber in?

Well, at this point it seems like you are going to have to break into the pipework....! It all depends how easy the access is - if the job is to be a reasonable one or a right sod. You'll have to drain down the large tank in the loft - stop the water refilling by tying the ball cock up. At the same time, check that the tank isn't full of sediment - you'll be surprised how much rust gathers there. (If its an old galvanised type, its got to be on its last legs by now).
If your pipework is copper, maybe there are some compression fittings that you can undo, but if not, the pipe can be cut using a proper pipe slice tool and rejoined later with a compression fitting.
If the pipework is plastic, the fittings can usually be undone carefully but they mustn't be forced off. Notice the plastic pipes always have an insert of some type when they are cut to be altered - the insert stops the pipe walls compressing when a fitting is screwed or pushed on.
So, expect a certain amount of residual water to spill when you open things up. If you undo a tap connector have a spare washer standing by. The only other thing I can add is that a blockage usually occurs on a bend! Just to avoid great wrath from 'er indoors I tend to isolate any appliance with valves of some kind (you can now buy cheap full bore isolators from Screwfix) - in this way you can work away without stress and the job goes much better.
Good luck if you decide to give it a go. Cheers John :)

I think the simple answer is get a plumber in

thanks for that

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