On Wed, 8 Dec 2010 09:22:08 -0000, ARWadsworth wrote:

I must look at my bill again. I am on E7 but have much less than
30%
on night rate. I stuck with it as I've a storage heater - kept it
as
standby if the combi breaks down. Can a combi 'sense' when there's
no
back-up?

With the money you have wasted on your electricity bill for the back-up
heating you could have switched over to a standard rate of electricity
and used the money saved to have a second combi installed as a back-up.

Possibly not that good. B-) But being on E7 unless you really are
using a good deal of cheap rate lecky is daft. E7 with a (singular)
storage heater only switched on if/when the primary heating fails
does not make economic sense. E7 with a single storage heater in
normal use is almost certainly more expensive than a decent normal
tarrif over a year.

--
Cheers
Dave.