Putting back an old metal wall sconce on a middle landing, that had been knocked loose, I made a point of connecting an earth (from the T&E) which didn't seem to have ever been connected. This made me a little unsure about the earthing of the circuit in general, and tracing the T&E back to a...
We've got a standard water tank with a bottom element fed from the economy7 wiring, and a top, "boost " element wired to the standard wiring.
Unfortunately it's quite a small tank and if someone has a bath in the morning
there is no hot water left, and the boost only heats the top of the tank...