Buzzing or humming noise from rear of unit, especially during start

Safety: Unplug the unit before adjusting any components.

Steps:

• Identify source: Listen carefully to determine if the noise is from the compressor area or when the unit fills with water.
• Secure tubing: Gently reposition and pad any copper lines that are touching the cabinet and vibrating.
• Check start relay: If the compressor hums briefly then clicks off, inspect and replace the start relay/overload.
• Valve noise: A brief buzz during fill is normal; continuous loud buzzing from the valve suggests it may be failing and should be replaced.