Isolate hot water feed so that bathroom taps can be changed All aspects of plumbing questions and answers, help, tips and information

[mikem]

I am changing the taps for the sink in the bathroom. I know that I need to shut off the water supplies to both taps. I have shut off the cold water supply by closing the cold water valve feed to the storage tank in the attic. My problem is shutting off the hot water feed. My hot water cylinder does not appear to have a valve to shut off the hot water supply to the house. I have tried to close the valve that feeds the cold water into the bottom of the hot water cylinder, however when I then open the hot bathroom taps the water flows from them and I can hear the attic storage tank filling. I also have an oil boiler and do not know whether this affects my situation or not. All I want to do is change the taps in my bathroom. Any help would be appreciated.

[johnb]

hi mikem simply turn off supply to storage tank in roof as you did before it takes time to drain this way but will eventualy empty tank in roof as your h/water feed is obviously not working yours john

[DONFRAMAC]

The cold feed you isolated to shut-down cold-flow to the basin, is obviously not your only riser, or the ball-cock valve would have no feed.
Also, the valve feeding cold into the base of the hot cylinder, could be passing,-- it happened in my first flat when a sparky was renewing the electric immersion element ;-- they had to break into the flat above and tie-up the ball at the loft header-tank which fed 3 flats. A new valve had to be fitted beside my hot tank, of a better type.
When I isolate my cold riser, I have to torque it firmly using a pair of pliers, and I leave cold taps open until the task is finished.