Incoming cold water main Isolation valve passing water when closed - replace?

[mikehardy]

Hi, I have noticed when the incoming main valve is fully closed it is still passing water possibly as much as 10% of normal flow. This valve is possibly 20 years old. Should I replace with what? The valve in question looks like an ordinary brass tap. Is this correct for mains isolation? if so replacing the tap washer will solve the problem? Hard water area.


Comments please,


Mike.

 

[hunterseye]

If your refering to the one under your sink, i'd just replace the tap.

 

[mikehardy]

Thanks hunterseye, Replace with the same type or a full bore ball valve?

Regards,

Mike.

 

[andyplumber2009]

Just done mine.
Note: you will more than likely have to replace the whole tap inc nuts, the nut on the incoming pipe (black pipe?) may be BSP and the new stop valves (few quid from screwfix/toolstation/merchant) will be metric. Get a pipe sleeve while you are there.
I would actually get the thing apart, cut and prep the pipe, go to a merchant with said pieces and get all at once. Hopefully your external road stop valve stilll works.

 

[hunterseye]

Me personally i'd replace with a like for like tap, once replaced open her up then give it a slight turn back to prevent it getting seized up if not in use.

 

[acecharly]

It should be a stopcock replace like for like it is possible your insurance will be void otherwise.

 

[hunterseye]

It should be a stopcock replace like for like it is possible your insurance will be void otherwise.

Apologies on my termonology 🙂

 

[JCplumb]

First and easiest option for me would be to replace the washer. When you have it open have a feel of the seat (the bit where the washer compresses on to), if it's smooth the new tap washer will be fine.

 

[kay-jay]

full bore lever valves are wras approved for stop tap purposes and wont void insurance