Need to do some maintenance to the power shower (work out why the hot flow seems to be restricting more and more, and the flow switch on the hot side doesn't work, which may be related).
Now, I have another shower over the bath, but it's never worked because it is low pressure and has double-check non- return valves fitted, which pretty much stop all forward flow too. Want this working so I can be without the power shower for a few days.
To fix either of these, I have to shut off the gate valves in the feeds from the loft tank. I discover most of them don't work at all, and the only one which does (power shower cold supply) only turns part way off.
So I will have to drain the tank. I turn off the tank feed, and order a set of full bore 1/4 turn valves.
Full bore valves arrive just as the tank runs out of water, which is a bit of good timing. Replace 4 gate valves with
4 full-bore valves (two 15mm, and two 22mm). Also, remove the non-return valves from the low pressure shower. (Looks like someone has already replaced the originals with giant 1.25" ones, presumably in an earlier failed attempt to improve the flow.) Refill tank a bit, check for leaks, none! Low pressure shower now works well enough as a backup.Refill the tank completely. Stopcock on tank inlet starts leaking through the shaft/stuffing box, so have to turn it off until I can see to that, although I now have the tank full. Check for leaks on my new plumbing, and everything is bone dry.
Half an hour later, I'm suddenly aware of a waterfall sound. Run up and check all the plumbing, but no sign, and I can't hear it now. Back downstairs, and I can hear it again. Eventually find one of the upstairs loos is pissing out through its overflow into the front flower bed, which is now a mud puddle. Fortunately, it has its own isolating valve, which I turn off. At that point, the isolating valve starts leaking through its screwdriver slot, sigh. By jiggling it with the screwdriver, I can stop it leaking.
Take the top off the torbeck valve in the WC, and it's got a bit of grit in it, probably something washed through as a result of emptying the tank. Put it back together, and check it works - it does. Glance back at isolating valve, which is now leaking again. Again, some jiggling with a screwdriver stops this, but I'm obviously going to have to swap it.
At least I can now turn off the water without having to drain the tank again.
BTW, haven't got as far as even looking at the power shower issue yet, which is what started this all off, and I've still got the isolating valve to replace and and tank inlet stopcock...