The sink tap replacement project (as usual) isn't going very well. They don't build them like they used ..... thank goodness. I can get an isolation valve fitted in place of the obsolete washing machine branch on the 'hot' feed, probably by draining down the tank, or getting enough of a vacuum from partial draining to stop further flow .... Not sure about the cold feed stop-cock. I'll try loosening off the gland first, to see if it's been done up too tight. It might be overly tight to help prevent a leak, and effectively stop the handle rotating.... What doesn't help is its location. At arms length at the lower edge of a unit. From the little I know about 'check-valves' I'm pretty sure they are to stop back-flow into potable/drinking water. The location of the 'check valve' should be on the outlet side of the branch so no dirty water can travel back into the mains. That valve being where it is, dirty water can mix with mains water held between the taps and the check valve. I'm pretty sure there should be one somewhere for the washing machine too .... Just found this ... I spent close to an hour gawping at this, wondering how to make it work ..... When I used to install small networks, and small telephone systems, I used to follow a regular/written protocol for everything I did. Not so much that I had (or have) a need to do things right (though I do), but if things are done to a recognised standard as it were, when maintenance is required no-one has to work out what they are looking at. It would be wrong of me to assume only 'bodgers' worked on this water system, but I am reasonably sure the people that did, managed to do the least necessary, with no care for any further work that might be required. "Take the money and run" springs to mind ... eg. Why are there no pipe clips? Everything is hanging off the sink taps.... So: First job, isolation valves. Then: source and change (the very nice) supplied rigid tap tails, for flexi's. (Proximity problem with straight ones.) And: source new check valve. (grrrr.) More to follow.