I just tentatively had a go at the drain cock, mainy to test my booster
pump in the inverted position - unpressurised water is hard to find in me
hovel - and found it's jammed fast, as far as I can see with a mirror the
suare bit is rounded, and I can't really get to it because it's 1/2" from a
side wall on about half a ton of brassware left over from the war.

That's a great start to the project.

My only thought is perhaps I can siphon out with a hose in the top after
I've drained the loft tank.

I don't want 114 litres of water over me floors, anyone help me on
minimising the flood?

mike