viv wrote:

Also, I noticed that when I deliberately left the heating/hot water
off completely for a week, the meter still went on running, and
clocked up half a cubic metre of gas. The only way I can keep the
meter from running is to turn the gas off at the mains.

Does your boiler have a pilot light? 0.5 cu. m of gas is only about 5.5
kWh, or 33 watts for a full week (168 hours). That's quite low as pilot
lights go - the one on my ageing Baxi accounts for about 120 W.

Also - as you seem to have a metric meter - make sure that your supplier
is aware of this and is not applying the times 2.83 conversion factor to
convert from the 100 cu. ft. 'units' of the more common imperial meter
into cu m. If this factor is applied when the meter is already metric
your bills will be high by a factor of almost 3. This has been known to
happen. Caveat emptor!

--
Andy