T i m wrote:
If it includes actually *needing* a bowl full of washing-up
temperature water several times a day than anything 'instant' is going
to have to be pretty powerful, as is any local water store, if not
either quite high capacity or high power (for reasonable recovery
time).

I was wondering about feeding an instant electric heater from a hot water
supply.

This might sound strange, but hot water supplies aren't always hot:
- there's the leg of cooler water before the hot water comes through
- in a tank system the boiler may not have run recently and the water be
lukewarm
- the storage temperature may be lower than you would want for washing
dishes

Is there any reason not to feed such a heater from say a 30-60C supply?

Theo