On Wed, 7 Oct 2020 16:11:49 +0100, newshound wrote:

Depending on the design, there is often a gate valve somewhere near tehe
tank (or possibly from cold cylinder to tank) that you can turn off
(recognisable by round pressed-steel handle).

Often won't move or, IME, turns 'off' but actually does FA.
--
Peter.
The gods will stay away
whilst religions hold sway