Unit emits a high-pitched whine or buzzing during operation

Safety: Turn off power before tightening or adjusting components.

• Tighten fixings: Check all mounting screws for the heater, cover, and internal components. Tighten as needed.
• Inspect fan: On fan-assisted models, clean dust from the fan and ensure blades are not rubbing.
• Check element mounting: Ensure the heating element flange is secure and not vibrating against the tank or casing.

Note: Persistent electrical buzzing from the PCB may indicate a failing component and should be checked by a technician.