Locating and turning off hot water valve?

The thin metal hot water pipe running to my bathroom sink has a small pinhole leak. I need to locate the hot water valve to stop the leak. Cold water valve is in mty kitchen and can be shut off easily.

I’ve locating 3 valve around my boiler cupboard but none seem to shut off if turned either way. The middle one stuck so I can’t shift it either way. Which one is the valve to the hot water taps??

I remember a plumber going in here years ago with a spanner or something and turning the water off, though I could be wrong.

Any help would be much appreciated.

Thanks