Electric Kettle Best buys from PainFree Shopping:

All of our Electric Jug  Kettles are cordless, have 360° docking bases, fill windows are  3kW fast boil (except our best buy economy and glass kettles) and selected for quality of manufacture and good performance. Some  have  extras features  you may need such as  pre-selected or controllable temperature settings. All have free  2yr guarantees or longer.

Some have nice design extras such as lighting  up the water when boiling. If you are not fussed about design or color and just  want a very good Electric  Kettle that does the job, then  then we recommend our best buy everyday Electric Kettle the Andrew James Lumigo a brilliant kettle at under £30 and it has a 2 year guarantee.
Brita Filter Kettles: Don’t bother wasting money on one, if you want pure water then filter your water before filling the kettle.

If you want to replace your existing kettle for a brand you are familiar with Russell Hobbs, Phillips and Morphy Richards all guarantee their kettles for 2 years. You must register your kettle with them online (Russell Hobbs will extend your guarantee to 3 years for free  if you do), so in case of issues you can deal directly with the manufacturer.