If you use the kettle, there is no escaping the fact that limescale will build up in it. It is important to clean it. As mentioned before, the lime particles can end up in your cup of tea. But it also causes the heat to conduct less well. Lime scale has an insulating effect. The harder the water is, the more lime there is in the water. And if this is so, limescale will build up faster in the kettle. As a result, your water will take longer to finally boil. So by regularly descaling your kettle, you prevent these two problems.