What happens if you don't flush your hot water heater?

If you don't flush your hot water heater, sediment and minerals from your water supply gradually accumulate at the bottom of the tank or inside the heat exchanger of a tankless unit, leading to a cascade of expensive problems. Initially, you will notice rumbling, popping, or banging noises as water trapped under the sediment layer boils. Your heater will become less efficient because the sediment acts as insulation, forcing the burner or heating element to work longer and use more electricity or gas, increasing your energy bills by up to 20 percent. Heating will become inconsistent, with lukewarm water or longer wait times for hot water. Over time, the sediment hardens into scale that can clog the drain valve, damage the heating element, and cause overheating that warps the tank or triggers the high-limit safety switch. The tank itself can corrode faster and develop leaks from the bottom, leading to water damage. For tankless heaters like Stiebel Eltron, failure to flush or descale in hard water areas can cause flow sensor failure, overheating, and complete failure of the heating chamber. Eventually, the unit will fail years earlier than expected, voiding warranties and requiring premature replacement.