How many cups of tea/coffee do you have a day?

[Tinbum]

That view is OK if your are already "paying" to heat the house AND the method of heating is just as efficient (or inefficient). But if you heat via a heatpump (assume a COP of say 3) then using the kettle to boil more water than you need will cost 3 x more for the "residual" heat.

I agree but, if say you have an extra litre of water in the kettle, which would be a lot, then every time you boil it your using less than 0.1KWh extra. Kettles are mentioned because they are high power appliances - but they are normally not on very long. Your a lot better off turning the thermostat down on the Hot water cylinder or swapping to LED bulbs. Every little bit does help though.

[marshman]

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