Changing bath - hot water wont turn off All aspects of plumbing questions and answers, help, tips and information

[nitro23456]

Hi

Changing my bath but can't get the hot water off. I have turned stop cock for cold mains and turned off the feed into the bottom of my cylinder. The hot water to my other hot taps stops but the bath still trickles (reduced but doesnt stop)

Some of you may remember my hot water cylinder thread with the fifth pipe - I am thinking that this fifth pipe may feed the bath tap only. There is no isolation valves in this line so I am presuming I will have to drain everyhting down completely.

When changing my basin (which is finished and done) the stop cock under the kitchen sink didnt turn off the cold to the bathroom basin, only the kitchen. I am therefore wonderng whether this will work to stop the cold feed into the header tank or not.

Any advice?

[chris_on_tour2002]

if the hot still trickles is likely that the shut off valve isn't fully closing off properly. as the bath is in 22mm and has greater volume this could explain why its only the bath tap and not the basin or kitchen as water will always find the path of least resistance. i had this problem in my bathroom, as it was only a slight trickle i cut the pipe and quickly put a 22mm isolator valve on it which you will want to do no doubt at some stage anyway. just put loads of towels down.

the only way to find out what that fifth pipe does it to try to follow it and see where it goes.

[quote] When changing my basin (which is finished and done) the stop cock under the kitchen sink didnt turn off the cold to the bathroom basin, only the kitchen. I am therefore wonderng whether this will work to stop the cold feed into the header tank or not.


do you mean the cold water tank feeding the cylinder? you don't need to shut off the main feed, just tie up the float valve before draining the cylinder. the bathroom cold tap is probably fed from the cold water tank not the main which is why it didnt shut off when you closed the stop cock. but it should shut off the suppy to the tanks unless they are getting the main feed via a different route. to find out close the stop cock then gently press down on the float valves in the tanks in the loft. if no water comes out then you will have your answer.[/quote]

[nitro23456]

I can see someone has replied but its not showing yet......

But another question! I am presuming (not having read the first reply) that the rising mains only feeds the kitchen cold and the header tank. Therefore the other colds (bath cold tap and bathroom basin cold which turn off with separate isolation valves in the airing cupboard) both come from the header tank? Is the actually safe to drink!!!

Back to my first post and getting the hot off to the bath. If I turn the stop cock off at kitchen and leave feed to the bottom of cylinder on and turn on all taps hot and cold to bath and bathroom sink (kitchen cold would stop) is this the best way to drain the header via the cylinder? Or should I shut off the stop cock (kitchen cold and header) AND the separate isolation valves to bath cold and bath basin cold respectively leaving only the hot bath, hot sink and hot kitchen on to drain it?

ie will leaving the respective colds on help or hinder?

[chris_on_tour2002]

the water in the tank should be safe to drink provided that the tank is well covered so no debris can get in and the tank itself is clean on the inside. used to be an issue with drinking water from the loft tanks as they used to be uncovered and as our water usage was not so great in days gone by the water would sit around going stagnant. in these days of multiple bathrooms, washing machines and dishwashers we tend to replenish the water in the tank pretty quickly and the water itself is treated with chemicals so its not the issue that it once was. historically this is why your kitched cold should always be mains fed as this is your drinking water supply.

if you want to drain the cylinder you will have to do it via the drain cock on the cylinder itself but there should be no need to completely drain it and no need to shut off the main. just tie up the float valve in the cold water tank (NOT the header tank for the heating) and turn on the hot tap (probably the lowest one in the kitchen would be best) and wait for the pressure to drop. there will still be water in the cylinder but no head in the tank to push it through.

[htg engineer]

If the bath is upstairs, opening the hot water tap downstairs with cylinder isolation valve closed, should stop any water coming out of the hot pipe for the bath, cut the pipe and then you can fit a ballofix valve. This will be easier for installing as then you just pipe from the ballofixto the new bath - which then can be isolated and turned on with ease to check for leaks etc.

If you want to renew the gate valve to the cylinder, so that in future the hot water can be isolated (also fix the leak from your other post - if not already fixed) Turn off the mains cold water, turn on all hot water taps and the cylinder will drain.

Stored cold water is not safe to drink - only water from the mains.

[chris_on_tour2002]

hi htg engineer - a query with your post:

[quote] "If you want to renew the gate valve to the cylinder, so that in future the hot water can be isolated (also fix the leak from your other post - if not already fixed) Turn off the mains cold water, turn on all hot water taps and the cylinder will drain."

Surely this won't actually drain the cylinder as the hot suppy from the cylinder is via the flange at the top. Therefore once the tank has drained and the system head is lost the water in the cylinder will just sit there with no pressure to push the water out the top?

Thus when you undo the compression fittings on the gate valve the water inside the cylinder has a route to escape. Wouldn't you need to drain the cylinder via the drain cock?
[/quote]

[htg engineer]

sorry - yes that would be right chris_on_tour2002.

[nitro23456]

[quote]If the bath is upstairs, opening the hot water tap downstairs with cylinder isolation valve closed, should stop any water coming out of the hot pipe for the bath[/quote]

This doesnt happen and thats my problem - doing this shuts off the hot to all taps apart from the bath hot tap which continues to flow (albeit at a reduced rate). Yesterday I left this reduced rate running for about a hour but it persisted and eventually turned cold - so somehow the CW Tank water is still getting through!

On all other taps the water shuts off completely.

[htg engineer]

You should not drink or cook with water from a storage tank in the loft and is not as fresh or safe as water that comes directly from the mains. You should use cold water from the mains for all drinking and cooking requirements.

Water companies are required by law to provide clean, safe, potable water. If the water entering our homes is contaminated then the water company is liable.

Water regulations state that, the water company/provider is responsible for the quality of the mains cold water. As soon as the cold water enters a tank or any storage device, the water company cannot guarantee the safety of this water - and is not their responsibility.

[chris_on_tour2002]

tie off the float valve on the CW tank feeding the cylinder (or turn off the stop cock) then run the taps until the water stops. once the tank in the loft has drained and the pressure lost then the bath tap should stop, if it doesn't then this is a sign that there is a problem and would require further investigation to find out why this is happening.