Freezer displays E8; ice buildup or temperature swings, defrost cycle irregular

Safety first: Disconnect power before removing control covers.

• Identify defrost control type: Some Whirlpool freezers use a mechanical defrost timer (often behind the kick plate or in the control housing), others use an electronic control board.
• Mechanical timer test: Locate the timer and slowly turn the advance shaft with a flat screwdriver until it clicks into defrost. Restore power and listen for compressor to shut off and heater to energize (sizzling on frost). If the timer does not advance on its own after 20–30 minutes, replace it.
• Electronic control: Enter diagnostic mode if available (see tech sheet) and force a defrost cycle. If the board does not initiate defrost and heater/thermostat are good, replace the control board.
• Check connections: Ensure all connectors to the timer or board are fully seated and free of corrosion.