Freezer makes a loud banging or knocking noise when the compressor starts or stops.

Safety: Unplug before working in the compressor compartment.

Steps:

• Inspect compressor mounts: Remove the rear cover and check that the compressor mounting bolts and rubber grommets are intact and snug. Tighten if loose.
• Reposition tubing: Identify any copper lines that may be striking the cabinet when the compressor moves. Carefully bend them slightly away from contact points.
• Monitor: If knocking persists and seems to come from inside the compressor, it may indicate internal wear. The unit can often still operate, but noise may worsen over time. Compressor replacement requires a professional.