Limescale is one of the biggest hidden threats to your boiler and heating system, particularly in hard water areas. This chalky calcium carbonate deposit builds up inside the heat exchanger, reducing efficiency, raising energy bills, and eventually leading to noisy operation, breakdowns, or costly repairs. Just a thin layer of limescale can cut efficiency by over 10%, forcing your boiler to work harder. Common signs include kettling sounds, cold spots on radiators, and reduced hot water flow. Prevention is far cheaper than repair: installing a limescale inhibitor, magnetic scale reducer, or water softener protects your system from the outset, while a professional power flush can restore older systems. By tackling limescale early, you safeguard your boiler’s performance, extend its lifespan, keep your energy bills low, and ensure reliable heating and hot water.