boiling kettle for washing up

[homedeeth]

which is more economical?

filling the kettle to the recommended maximum level and boiling it twice for washing up....or out of the tap using economy 7 tariff?

i have no hot water in my flat at the moment other than out of the shower. there's no gas supply as it's all electric and i haven't got the heating on cos it's coming up to summer

[rov1200]

Depending on your electricity tarriff there may be a 3:1 difference in cost of electricity.

But there are substantial differences. The hot water tank will never reach boiling point unlike the kettle. The amount of water in the kettle is a fraction of that in the tank so you are only heating what you require. There is a certain amount of heat loss in the tank so this has to be replentished. The cost of boiling a kettle is easily calculated.

Most kettles are usually 3 KW. That means for every hour it will use 3 units. The cost of a unit is given with your bill.
eg if a unit costs 15p and the kettle takes 4 minutes to boil the cost would be 15x3x4/60=3p x 2=6p

Therefore the kettle would win hands down.