I used to use a kettle but have now put one of the Screwfix electric
tank heaters under the sink, on a second tap.
Perhaps not the greenest solution but very convenient.

It's probably not as bad a solution environmentally as you think. There is
less wastage of heat and water (no dead legs), which is good. Also, remember
that the carbon dioxide footprint of using electrical energy isn't worse
than the gas in proportion to the cost. Some electricity is not carbon
fuelled. The additional cost is as much about distribution and generation as
thermodynamic inefficiency.

Christian.