Refrigerator shows H24, heavy frost on evaporator, cooling weak, fan noise may be restricted

Safety: Unplug the refrigerator. The defrost heater operates at mains voltage and can be hot.

• Step 1 – Manually defrost: Remove food from the affected compartment. Open doors and allow ice to melt naturally, or use a hair dryer on low to speed up. Protect the floor from water.
• Step 2 – Access heater: Remove the rear interior panel to expose the evaporator and defrost heater (usually a metal or glass-encased element beneath or around the coil).
• Step 3 – Visual inspection: Look for breaks in the heater element, burnt spots, or disconnected wires. Check the thermal fuse/bimetal thermostat mounted on the evaporator for signs of overheating.
• Step 4 – Continuity test: With a multimeter, test the heater and thermal fuse for continuity. Replace any open components with genuine Panasonic parts.
• Step 5 – Wiring and PCB: If heater and safety devices test good, the main PCB defrost relay or control logic may be faulty. This typically requires PCB replacement by a technician.