Stubborn rings in the bathtub, crusty boilers and taps that just refuse to clean. These are all signs of limescale build-up. But just what exactly is limescale, and why does it lead to a catalogue of plumbing problems?
Rainwater naturally contains few impurities and remains ‘soft’ if it runs over rocks such as slate or granite. But if rainwater flows through soft rocks such as chalk or limestone, it absorbs calcium and other minerals and becomes ‘hard’ water. The British landscape is dominated by soft rocks and six homes in every 10 are supplied with hard water.
Hard water becomes a major problem when it’s heated above 55°C or left to stand for a long period of time. Mineral deposits begin to form as the water evaporates and covers hard surfaces such as taps and kettles, which can be difficult to remove.
The most damaging effects of limescale, however, can go unnoticed for years. Hard water has around 300mg of dissolved minerals in every litre, meaning that a four-person household can be subject to 70kg of limescale every year. The pesky deposits stay hidden inside plumbing systems and central heating pipes, until problems such as failing boilers and blocked drains highlight the problem.
Limescale can also increase the cost of energy bills. Deposits coat the elements in washing machines, dishwashers and boilers as well as the kettle, making them less energy-efficient. According to British Water*, just a 1.6mm coating of limescale on a domestic heating element can make an appliance 12% less effective. Not only does this make appliances more expensive to run, it also causes them to wear down more quickly or even burn out suddenly without warning.
The quickest and cheapest way to deal with limescale is with a homemade cleaning solution. Malt vinegar and lemon juice will dissolve thin layers of mineral deposits on kettles and taps, but are not practical solutions for cleaning a larger appliance such as a washing machine.
A more effective solution is to treat hard water before it enters pipes or appliances. Water softening tablets swap the calcium in hard water for sodium, which is more likely to stay dissolved when heated.
Water conditioning is the most recent high-tech tool in the battle against limescale. Hard water is exposed to a low level magnetic field, which causes the mineral impurities to come together in one mass. These clumps provide a surface for dissolved minerals to cling to when water is heated or left to stand, which prevent them from sticking to hard surfaces such as pipes. To find out more information on getting rid of limescale or to help you deal with this issue effectively, contact a plumber in your local area.