E5 appears on the display; unit may not respond correctly to temperature settings.

Safety: Turn off power at the breaker or unplug the unit before removing any trim or control panels.

Steps to resolve E5:

• Power cycle: Disconnect power for 5–10 minutes, then restore. If E5 reappears, continue.
• Access control panel: Remove the door trim or upper control housing screws to access the user interface board and ribbon cable.
• Inspect connections: Check the ribbon cable for kinks, cuts, or burn marks. Reseat both ends firmly into their connectors.
• Check for moisture: Look for condensation or corrosion on the interface board. Dry gently and clean light corrosion with electronics cleaner if minor.
• Replace interface board: If the display is erratic, buttons do not respond, or visible damage is present, replace the user interface board.
• Main control board: If a new interface does not resolve E5, the main control board may have a communication fault and should be replaced.

Note: Handle electronic boards by the edges and avoid static discharge by grounding yourself before touching components.