Limescale is mostly calcium carbonate that is left behind by hard water. Hard water contains a higher concentrate of dissolved rock minerals such as magnesium and calcium. When conditions are right, magnesium and calcium chemically react with surfaces, forming rock hard limescale.
The limescale will often appear as a white-ish chalky substance that is hard and will build-up on any surface that the hard water has contact with such as taps, sinks, tiles and boilers.
If left, the limescale will begin to effect the energy efficiency of your appliances and can cause water flow restrictions, blockages and even breakdowns. These problems cause higher energy bills or the cost of having to replace appliances prematurely.
Unless you have soft water or install a water conditioner, such as an Aquabion, then there really is no way to avoid limescale build-up and the ongoing effects it will bring.
Find out more about the Aquabion and why it is the best alternative to a salt based water softener.