Electric kettle switches on and off every 10 seconds and doesnt boil

Just fill it up with water and boil, then empty and repeat a few times, or put in equal amounts of white vinegar and water and leave it to soak overnight. Just make sure you rinse it really well in the morning

This answer may be too late but first clean this thoroughly with vinegar. Try now to see if anything changed but do a very thorough clean.

The switch has to turn off when the water boils as the heat generated must cut off the switch. If this wont work the bimetal is not working and the switch is not responding.
You will need to replace the switch. Please contact the dealership for the spare.
check this link for spare:
http://www.espares.co.uk/brands/kettles/p/1102

No! you have clearly a manufacture defect or a design issue, I would take it back and select a different brand if possible or your money back.

Unfortunately the problem is in the switch mechanism, and will need to be replaced to correct the problem. My sense is it would be cheaper to replace the kettle than trying to find somebody to repair it.

I think you would only solve this problem by cleaning the thermostat contacts, or replacing the thermostat which wouldn't be worthwhile as it's likely to be cheaper to buy a new kettle.
Besides this , just getting into the kettle needs special 3 tongue screwdriver and then a certain technique to open it up without damaging the plastic parts. Im'e afraid its a throw-away world now and its not good .

Our first Smart Kettle was great and worked well for years, finally died so we bought another. Right from the first boil it seemed to boil for about 2 or 3 minutes before turning off and then either didn't boil or made beeping sounds when not being used so after a couple of weeks we returned it and it was replaced. Great. But now this new one seems to boil and boil before turning off so maybe they are just faulty now. Any suggestions?

This can happen on new mettalic kettles, the aftertaste may dissapear after a while with use as it did with mine.

The termostat or electronic controler is not working properly.

Jerry G.