Scale, primarily composed of calcium and magnesium deposits, accumulates inside plumbing systems and appliances that heat water. This buildup occurs because hard water, rich in these minerals, releases them when heated, causing them to precipitate out of the water and adhere to surfaces. A tankless water heater, due to its design involving rapid heating within a small heat exchanger, is particularly susceptible to this mineral accumulation.
The presence of scale significantly reduces the efficiency and lifespan of the appliance. Scale acts as an insulator, hindering the transfer of heat from the heating element to the water. This necessitates the heater to work harder to achieve the desired water temperature, leading to increased energy consumption and higher utility bills. Over time, excessive scale buildup can cause the unit to overheat, potentially damaging components and requiring costly repairs or premature replacement. Moreover, restricted water flow due to scale accumulation can lead to inconsistent water temperatures and reduced hot water output.