Heater makes loud clicking, humming, or buzzing noises during operation.

Safety: Turn off power before tightening or touching internal components.

• 1. Check mounting: Ensure the heater is firmly fixed to the wall and that all mounting screws are tight.
• 2. Inspect elements: Look for loose element mounting nuts or supports. Tighten according to Kospel specifications.
• 3. Relay noise: Some clicking from relays is normal, but loud buzzing may indicate a failing relay or contactor. Replace the main PCB or relay module if necessary.
• 4. Descale: If you hear kettle-like boiling or popping sounds, descale the heat exchanger to remove limescale.