Dualit kettle turning off before boiling? My solution?

To those with a Dualit kettle that switches off before boiling point is reached - I've just made mine work again. I was cleaning it up to return to the store, and realised it has started to work properly again. First I put half a pint of white wine vinegar into the kettle, turned it on to slightly heat up the vinegar and left it for an hour. Then I used a clean washing-up brush to gently remove the now softened limescale inside the kettle. Rinsed the kettle out a couple of times to remove the vinegar, filled the kettle with clean water and put it back on to heat up. To my amazement the kettle now reached boiling point and turned itself off. I've repeated the filling and boiling and there's no smell of vinegar and the kettle works. Bottle of white wine vinegar £1 - result.