Replacing the stopcock

[blackbirdxx]

Hi,
Hopefully a straight forward question from a non plumber...

I need to change the stop cock under my stairs. I have an unvented system with an upstairs cylinder. Turning the supply off in the street should be straightforward as a new meter was recently installed. My concern is that if I switch the supply off in the street and allow the indoor taps to run dry, is there anything else I need to do prior to disconnecting the stopcock? What I don't want is a tank full of water over me when I disconnect the stop cock. Do I need to drain the cylinder down as well?
Thanks in advance for your help.

 

[CountryFan]

No need to drain the cylinder, just as you suggest, run the taps off. You may get a leg of water in the pipe, so if there’s a drain off on the existing- use it, if not then fit one for future maintenance.

 

[blackbirdxx]

Many thx for the speedy response

 

[HERTS P&D]

What size pipe is your incoming water main?

Andy

 

[blackbirdxx]

What size pipe is your incoming water main?

15mm incoming pipe from water main to stopcock. 15mm from stopcock to upstairs cylinder.

 

[HERTS P&D]

Fit one of these:

https://www.screwfix.com/p/pegler-pb300-compression-full-bore-15mm-ball-valve-with-blue-handle/11085?tc=LB4&gad_source=1&gad_campaignid=19822796606&gbraid=0AAAAAD8IdPw6dWKY-G2tUi4OwAndBkna4&gclid=Cj0KCQjwlrvBBhDnARIsAHEQgOSmgxQX7hZevfA1eaX87gRHJXmcVXQSlAXdwjio2FZhUgUVzBiP68oaAuh7EALw_wcB&gclsrc=aw.ds

Andy