"John Smith" wrote
| Our house had electric heaters with Economy 7 installed back in, oh -
| the 70s. ... Anyhow, basically, we have a system which controls
| our heating by switching the heaters on at 1AM and switches them
| off at 7AM.
| In the night, during the winter, the house is warm.
| In the day the house gets cold very quickly and there is no way to
| turn the heaters on.

Sounds like your flaps are stuck open. The problem is the heaters are
letting all the heat out at night instead of holding it for when it's wanted
later.

The heaters should be charging up with heat between 1-7am but should not
release that heat until you open a flap inside. There should be an 'output'
control on the heater. That should off OFF overnight and during the morning,
then mid-afternoon or early evening turn the output up and the heater will
release its heat so your house is warm in the evening. If you turn the
output up too early in the day you'll run out of heat before tea-time. Turn
the output to OFF before retiring to bed. You will probably hear the flap
moving as you adjust it.

It is quite likely that the system is undersized and the house is
inadequately insulated.

| The heating is controlled by a black box with a clear plastic
| cover over it in which there is a metal clock type mechanism with
| 4 pins in it. I assume that, if I had the cover open, I could move
| the pins around and get it to change so that the heaters came on
| for, say, a couple of hours during the day as well as the usual
| night-time. Can I do this?

The timeswitch could be doing one or both of two tasks:

1. Changing your meter from High Rate to Low Rate. In this case the
timeswitch should be sealed and breaking the seals would be a criminal
offence.

2. Turning your heaters on and off at the right time. In this case your
meter may be changed over by a separate teleswitch (radio controlled).

If the timeswitch is *only* doing 2. then you could alter it, but your
heaters would then be taking in electric mid-afternoon at that
ever-so-expensive High Rate. And storage heaters aren't designed for
instantaneous heat, so you might as well plug in a fan-heater.

Owain