Boil water daily: 9 out of 10 households use their kettle incorrectly.

 

This sounds like a typical, sensationalist clickbait headline from the internet – but there’s actually a grain of truth to it! It’s usually less about acute health risks and more about wasted energy, limescale problems, and taste.

The three most common mistakes that almost everyone makes unconsciously relate to the following points:

 

1. Boiling too much water (“stockpiling”)

This is a classic mistake. Filling the kettle to the maximum for just one cup of tea wastes a lot of electricity and time. If this happens several times a day in 9 out of 10 households, it adds up to a considerable sum on the electricity bill over the course of a year.

The solution: Only fill it with as much water as you actually need (but be sure to check the minimum fill level of the kettle).

2. Leaving water in the kettle

   Many people simply leave the remaining water in the kettle to boil it again next time. The problem with this:

Limescale buildup: Stagnant water encourages limescale to form on the heating elements. A layer of limescale acts like insulation – the kettle takes longer to boil and consumes even more electricity.

Taste: Boiled water loses oxygen. If it cools down and sits in a plastic or stainless steel container for hours, it often tastes stale when boiled again.

3. The myth of “toxic” reboiling

   You often read warnings in such articles that water boiled several times becomes “toxic” or carcinogenic because pollutants like nitrate or fluoride concentrate. Scientifically speaking, this is nonsense.

While a minimal amount of water does evaporate during boiling, theoretically increasing the concentration of minerals in the remaining water slightly, this effect is so minuscule with normal tap water that it is completely harmless. Even harmful substances from the kettle’s material (such as nickel or plasticizers) do not leach into dangerous quantities from modern, tested kettles.

In conclusion: You’re not putting yourself in danger by using the kettle “incorrectly”—but you are wasting money on electricity and causing the kettle to build up limescale faster.