In article ,
TonyK wrote:
Should the cylinder be switched off Monday - Fri am allowing the water
to cool and reheat from what I asume would be almost cold on Friday pm.
Or, is it more energy efficient to leave it on and let the thormostat
regulate power consumption to keep it up to temp throughout the week?

A little lateral thinking says that electricity used for heating water is
very nearly 100% efficient in what it does - ie there is no waste heat, as
there might be with a less direct method, ie a gas boiler.

However, no insulation can be 100% efficient, so there will be some heat
loss. So switching off when not required must be the cheapest option. It
might not be the most convenient, though, given the time needed to re-heat.

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*I took an IQ test and the results were negative.

Dave Plowman London SW
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