dH or defrost heater error on Café refrigerator; unit may show warm temperatures or excessive frost on evaporator.

Safety first: Unplug the refrigerator before accessing the evaporator area. The defrost heater and metal fins can be sharp and may still be hot after a cycle.

• 1. Inspect for frost pattern: Remove freezer drawers and the rear interior panel to expose the evaporator coil. Heavy, solid ice covering the entire coil indicates a defrost failure.
• 2. Manual defrost: Place towels at the bottom of the freezer. Allow the unit to sit unplugged with doors open until all ice melts. Do not use knives or screwdrivers to chip ice.
• 3. Check defrost heater continuity: With the heater disconnected and using a multimeter, test for continuity. An open circuit indicates a failed heater that must be replaced.
• 4. Test defrost thermostat: The thermostat (bi-metal) should show continuity when cold (below its closing temperature). If it remains open when cold, replace it.
• 5. Inspect wiring harness: Look for burned connectors or broken wires between the heater, thermostat, and main control board.
• 6. Control board evaluation: If heater and thermostat test good but no power is sent during a forced defrost test, the main control board may be defective and should be replaced by a professional.