Slice the lemon in half using a knife.
Squeeze out the juices into the kettle.
Rub the lemon on the outer part of the kettle.
Put the lemon slices into the kettle.
Then, pour the water about halfway.
Turn the kettle on and let it boil.
Carefully shake the contents of the kettle.
Allow it to cool for a few minutes.
Add some water but do not fill it to the brim.
Turn the kettle on and allow it to boil.
Give it a slight shake.
Allow it to cool down for a few minutes.
Use a sponge to rub the outside and inside of the kettle.
Drain the water and lemons.
Once contented, wipe it with a cloth or a kitchen towel.
There you have it, a limescale-free kettle!