Jackson dishwasher displays E20 indicating an internal memory or configuration error in the control board.

Safety first: Disconnect power before handling control electronics. Use ESD protection.

• Power cycle the unit: Turn off power for several minutes, then restore. Some transient memory errors clear on reboot.
• Check supply quality: Verify that the dishwasher is supplied with stable voltage within Jackson’s specified range. Install surge protection if power quality is poor.
• Reload or reset configuration: If the model supports it, enter service mode and reload factory parameters or reset to default settings following the service manual.
• Inspect control board: Look for obvious damage such as burned components or corrosion. If present, replacement is required.
• Replace control board: If E20 persists and configuration cannot be restored, install a new Jackson-approved control board programmed for the specific model.

Because incorrect programming can affect wash times and sanitizing, ensure any replacement board is correctly configured for the dishwasher model and options.