Difficulty turning off downstairs hot water

[alwaysccurious]

Hi all,
I am trying to learn how to turn off my downstairs hot water. The red lever downstairs in my utility room under the sink only turns off cold water. So low and behold, I turn off both of the red levers upstairs in the hot press. One lever turns off the upstairs hot water. When I turn off the other level, the hot water downstairs squeaks and puffs a bit but still flows from the taps strongly. What am I doing wrong? Many thanks

 

[Elkato531]

You need to trace the pipes from the valves in the airing cupboard upstream and downstream. Does one come from the loft tank and feed into the base of the hot water cylinder?
If you close this valve you will stop water entering the cylinder. When you open a hot tap, water will flow until the pipework above it is empty and then stop. The pipework empties because air can get in via the vent pipe.

 

[alwaysccurious]

You need to trace the pipes from the valves in the airing cupboard upstream and downstream. Does one come from the loft tank and feed into the base of the hot water cylinder?
If you close this valve you will stop water entering the cylinder. When you open a hot tap, water will flow until the pipework above it is empty and then stop. The pipework empties because air can get in via the vent pipe.

Hi, thank you! This is what I tried to do. I closed both the valves in the upstairs cylinder. The hot water stopped flowing upstairs but continued downstairs (although it did splutter a bit). Should I just have left the downstairs hot taps running for a few minutes? Would that cause an airlock upstairs? I am trying to replace downstairs taps

 

[dilalio]

If cold feed to cylinder has a "working" isolation valve, turn that off.
Then open ALL hot outlets.
Hot water will eventually stop everywhere and downstairs pipework will empty as you have left upstairs taps open, releasing any vacuum.
Yes, potentially air locking but that comes with the territory.

 

[alwaysccurious]

Thank you so much. So here are the two valves in the upstairs cylinder. When I turn them both off, the hot water in the upstairs taps stops automatically. However, the hot water keeps running downstairs (splutters a bit!). I kept downstairs hot taps running for a few minutes and the water kept flowing strongly. Do I just wait longer? I didn’t expect that much water to be in the pipes to empty so I’m afraid I’m making a silly mistake

 

[dilalio]

You have to trace the cold supply into the cylinder and go upstream on that pipe to see if there is an isolator (gate valve) on it. If there is and it works, this will stop any hot water coming from top if cylinder and to hot outlets.

If this doesn't stop after say 10 mins then you may be getting crossover somewhere... Like a mixer valve allowing cold water into the hot circuit.

 

[terryplumb]

Gate valves are notorious for not fully closing ,and probably why you still have running water when closing the gate valve on the cold supply to hot water cylinder.
Tie up the ball cock in the loft tank and open every hot tap ,they will drain the loft tank in about 10 minutes, the hot water cylinder will still be full of water,but water will cease to flow from hot taps. It would be wise at that time to replace the gate valve for a full bore lever operated isolation valve on the cold supply to cylinder.