Needed to change an isolation valve on the upstairs cistern. Turned the main supply off and checked by turning on the kitchen tap. (No water)
Once the valve was removed water started to seep and then pour from the pipe. Pluged with the emergency blocker. (Thumb) Turned the bath tap on and water constanly flowed.???? Turned tap off and quickly replaced valve.
When I turned the mains back on it appeared a tank was being refilled in the loft.
What is going on?
Are things on a different systems?
How do I procede so I can replace the valve without flooding the house?

Thanks

Nige

Kitchen taps are mains fed, everything else is from tank if u have one. Water off, bathroom taps on and let it drain and your ready to change the valve

Or isolate the valve from the tank in the loft.

If your lucky there might be an isolator tap on the feed from loft tank into the system, would save draining the tank.

Have such a tap on mine, which was very handy when re plumbing the bathroom.

Thanks very much for the info. Had an idea that the solution was something along those lines.

Mucho Thanks to all.

Nige

Our tank in the loft had the ballcock thing like in the toilet you could prop up, had to do that when we changed the central heating pump