Controller displays E4 and smoker will not start heating cycle

Safety first: Disconnect the smoker from power before removing any panels.

Reset and inspect:

• Hard reset: Unplug the smoker for at least 5 minutes to allow the controller capacitors to discharge. Plug back in and attempt to power on. Sometimes this clears transient E4 errors.
• Check supply voltage: Verify the outlet is providing stable voltage (typically 120V AC in North America). Avoid using long, undersized extension cords that can cause voltage drops.
• Inspect wiring harness: Remove the controller cover and inspect the ribbon cable or harness between the display board and main control board. Ensure all connectors are fully seated and not corroded or burnt.
• Look for board damage: Examine the control board for burnt components, cracked solder joints, or signs of moisture intrusion. If present, the board should be replaced.
• Try factory reset (if supported): Some Smokin-It digital controllers support a reset procedure (e.g., holding specific buttons while powering on). Refer to the model's manual and perform the reset if available.

Next steps: If E4 persists after reset and wiring checks, the controller is likely defective. Replace the complete Smokin-It digital controller assembly or have a technician do so.