In message , Johny B Good
writes

If I were you, I'd certainly be making some fairly basic tests to
look for either a metering error or a hidden 'phantom load' (Bill
Wright can recount a story or two relating to 'mystery phantom loads'
if ask him nicely :-).

Yes please :-) That is another possibility. When we moved in 12 years
ago, I climbed into the loft and found minimal insulation and a tube
heater beside the CW tank. There are three lofts here, due to the
construction of the house, one of which I have never been in.

Anyway, I am sort of reassured, particularly by Mark's comments, that
the usage is us being careless, or carefree.

Three plans. Firstly, tomorrow, turn off everything, and make sure the
meter actually stops.

Secondly, use a usage meter as first mentioned by Andrew.

Finally, run a test with just one known item running, to check the
accuracy of the meter.

Oh, and cut out the obvious excesses. Two desktops on 24/7. TV and box
on standby, but rarely used. Thinking back, we watched a few Harry
Potter films last Christmas, a few World Cup matches earlier this year
and the England match a couple of weeks ago, yet the TV and box are
always on standby. Ridiculous.

--
Graeme