Error code Er dH displayed, refrigerator may show signs of heavy frost on evaporator and poor cooling.

Safety first: Disconnect power before accessing the evaporator area. Use insulated tools and avoid contact with sharp fins.

Steps:

• 1. Visual inspection: Remove freezer or fresh food rear interior panel (depending on model) to expose the evaporator coil. Look for a solid block of ice covering the coil, which indicates defrost failure.
• 2. Manual defrost: Unplug the unit. Place towels and a pan to catch water. Use a hair dryer on low to melt ice from the coil and surrounding area. Do not use sharp tools to chip ice.
• 3. Locate defrost heater: The heater is typically a glass or metal tube at the bottom or woven through the evaporator. Inspect for visible breaks or burn marks.
• 4. Test heater continuity: Disconnect heater wires. Use a multimeter on ohms to check continuity. A reading of OL (open) indicates a failed heater that must be replaced.
• 5. Check defrost thermostat/bi-metal: The thermostat is clipped to the evaporator tubing. When cold (below freezing), it should show continuity. If it remains open when cold, replace it.
• 6. Inspect defrost thermistor (if equipped): Some Kenmore models use a thermistor instead of a bi-metal. Measure resistance at known temperatures and compare to service data. Out-of-range readings indicate replacement is needed.
• 7. If heater and sensors test good: The main control board may not be initiating defrost. Inspect the board for burnt spots. Replacement of the control board is often required and may be best handled by a technician.