Changing sink taps to a basin mixer .. how do I isolate water?

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hbcgar
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Changing sink taps to a basin mixer .. how do I isolate water?

Post by hbcgar »

Hi, I need to replace the taps in a sink unit and will go from two taps to a mixer. I have watched a video and it seems straight forward enough but there are no isolation valves beneath the sink. How can I switch off the hot & cold water? I have looked into the area that houses the hot water boiler and it is all confusing with heating pipes etc. Up in the loft where the cold water tanks is there is a pipe leading down through the ceiling.
The sink unit is in the bathroom on the first floor.
Grateful for any advice.
dewaltdisney
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Changing sink taps to a basin mixer .. how do I isolate water?

Post by dewaltdisney »

It depends on your heating and hot water system. If it is a combi boiler then just turning off the main stopcock will stop the water running all over the house as a rule. If you have a separate hot and cold tank you may have to drain the tanks as well.

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yartin
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Changing sink taps to a basin mixer .. how do I isolate water?

Post by yartin »

Call a plumber if you can't isolate hot & cold

If you have hot water cylinder, there should be a stopcock, usually on the pipe coming down from the loft feeding the cylinder.
If you have a kitchen, the cold water stopcosk should be under the sink or possibly a foot or so to the right or left on the sink. If it is hidden behind units or appliances then there were will be a stopcock on the pavement you can use.
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hbcgar (Fri Jul 03, 2020 6:57 am)
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wine~o
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Changing sink taps to a basin mixer .. how do I isolate water?

Post by wine~o »

Normally a gate valve on the feed to the hot water cylinder will isolate the Hot water side. They are prone to failure though. Make sure you fit isolation valves to the pipes while changing the taps.
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Changing sink taps to a basin mixer .. how do I isolate water?

Post by dewaltdisney »

I don't think I have ever managed to turn off a gate valve. They are always so stuck you get worried about fracturing the pipe putting pressure on it. Draining down is easier :lol: Hopefully, the OP has a combi

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Changing sink taps to a basin mixer .. how do I isolate water?

Post by wine~o »

Gate valves work fine provided that you open and close them say every 6 months.

The problem is, no-one ever does. (myself included) :oops: :oops:
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Changing sink taps to a basin mixer .. how do I isolate water?

Post by wes56 »

If gate valves have been used or are being fitted then its best to fully open the valve and then wind back a full turn so that however jammed it feels it can still be turned without breaking the stem.

The best isolating valves are Ball Valves that c/w levers. They always work and rarely leak.
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hbcgar (Fri Jul 03, 2020 8:04 am)
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hbcgar
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Changing sink taps to a basin mixer .. how do I isolate water?

Post by hbcgar »

wine~o wrote:
Thu Jul 02, 2020 4:15 pm
Normally a gate valve on the feed to the hot water cylinder will isolate the Hot water side. They are prone to failure though. Make sure you fit isolation valves to the pipes while changing the taps.
Hi, I have been into the loft there is one large tank and a pipe that goes down into the flooring with a red tap. I think it goes straight into the boiler as it is roughly underneath where the tank in the attic is. If I turn off the red tap and drain the boiler would this work?
Also located in the boiler cupboard there is a thicker cold water pipe, with red tap, that runs straight up, presumably to the tank, not via the boiler. I have also located a cold water pipe in the utility room. It is blue, relativity wide and has an old fashioned style tap. It is also earthed. The pipe leading off is a smaller copper pipe, there is a junction there also, one pipe goes direct to the sink tap, the other pipe? The gauge of this copper pipe is smaller than the one that runs in and out of the pipe in the boiler cupboard.
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Changing sink taps to a basin mixer .. how do I isolate water?

Post by dewaltdisney »

Have you tried turning off the main stopcock and opening the basin taps as a test? A photo of the tank set up would help see viewtopic.php?t=14693&start= how to post pictures.

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hbcgar
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Changing sink taps to a basin mixer .. how do I isolate water?

Post by hbcgar »

dewaltdisney wrote:
Fri Jul 03, 2020 7:51 am
Have you tried turning off the main stopcock and opening the basin taps as a test? A photo of the tank set up would help see <span class="skimlinks-unlinked">viewtopic.php?t=14693&start</span>= how to post pictures.

DWD Hi, I took some photos of the tank and boiler. The three pipes going into the boiler are all hot so I am not sure where the cold water supply comes from? There is a pump that serves two showers in the photos the cold water pipes do not go to the boiler? Id there another tank somewhere?
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