On my hot water cylinder in the airing cupboard is a pipe coming from the ceiling and entering the tank at the bottom - it also has a drain cock on it. This is the cold water supply pipe and mid way to the ceiling is a stop tap lever - if I operate this no cold water can enter the tank and the hot taps cease flowing in about 30 seconds. The tank remains full but nothing comes out because nothing can get in. I lose about half a gallon of water.
With such simple and easy control you may well not need an isolator at all.
Good luck...
Peccavi
January 2010
howtomendit.com for free repair help, information and advice.
