Need to turn off water feed, Help.

[Gholt]

Hello,
We recently had our very old back boiler condemned, which is downstairs at the back of the gas fire.
So for hot water we are using the immersion heater.
But to make matters worse we have a leak in the loft from the water tank that feeds the radiator system, now I need to stop it refilling, I have lifted the ball cock but the stop ball cock is old and just slightly dripping, there fore over a few days refilling the rad system, then the water tank start to leak again.
My Question is the is a stop tap next to hot water storage in the airing cupboard, is this the feed for only the Radiator tank or would this supply water to both the rad tank and the hot water storage?

Thanks in advance for any help!!!!

 

[Gasguru]

If there's a stopcock near the cylinder this would probably feed both the large cold water cistern and the smaller feed and expansion cistern.
Isolate with this stopcock and cap off the pipework feeding the smaller cistern.

 

[Gholt]

Thank for reply Gasguru, It does look like it feeds both, just been looking again at it, will try and cap it off!