Water heater vs boiling a kettle

[OhWesternWind]

for doing the washing up - which is cheaper?

I am sure someone wise on here will know

What sort of water heating do you have? If you have a combi boiler that heats the water only as you use it then possibly that is cheaper but if you have to heat a whole tank to just use a sink full of it then maybe the kettle?

I am guessing though rather than being wise

Sorry, should have said it is a combi boiler. But you have to run a lot of cold and luke warm water before it gets hot enough to wash up.

Combo boiler definitely cheaper, as it only heats the water to about 60 degrees, and loses less to steam. Unless of course you're making a cuppa and have some hot water left to make up the water level to the kettle's minimum, in which case why waste it?

cost of electricity per unit heat is between two and three times as expensive as gas.

So if you are just heating enough for a teapot, kettle is cheaper (as there is none lost warming the pipes).

If you are filling a sink, the losses in the pipe are not significant (unless you have an unusually long pipe run, in which case, put plastic foam pipe lagging on it, such as Climaflex.

Ooh Im interested in the answer to this!
Ive got a combi boiler but find it much more convienient to use my kettle to get hot water for washing up.
Im fascinated to find out whether I ought not to do that!!