Various kettles have a fine mesh filter in or near the kettle’s spout that prevents lime scale getting into drinks. Some kettles may also use a built-in water filter that removes impurities from the water as it is poured into the kettle.
Built-in water filters are cartridges that need to be changed occasionally. Some kettle models feature indicators that let the individual know when the filter cartridge needs to be replaced.
Lime scale is a hard, chalky deposit that can add wear to the kettle and diminish the fresh taste of water. Kettles without fine mesh filters may gather lime scale buildup. This buildup may also occur if the fine mesh filter does not fit securely.