EcoSmart unit makes loud clicking or buzzing noises when hot water is used.

Safety: Turn OFF power before tightening internal components.

• Identify noise source: Remove the front cover and carefully listen (with power ON and water running) to locate the noise area, then turn power OFF before touching anything.
• Tighten hardware: With power OFF, tighten mounting screws for heating elements, bus bars, and the control board. Ensure nothing is rattling.
• Descale heater: If noise is accompanied by popping or crackling, scale on elements may be causing uneven heating. Perform a descaling procedure.
• Relay noise: Some clicking from relays is normal, but loud buzzing may indicate a failing relay or triac on the control board, which may require board replacement.