Thermostat displays E9 and touchscreen or buttons do not respond properly

Safety: Turn OFF power to the HVAC system at the breaker before removing the thermostat from the wall.

• Inspect screen: Look for cracks, bulges, or signs of moisture under the glass. If the screen is physically damaged, it will need replacement.
• Reseat thermostat: Remove the thermostat from the wall plate and carefully re-seat it to ensure the low-voltage and data contacts are making good connection.
• Clean edges: Use a dry cloth to gently clean around the edges of the screen and housing. Do not use liquids or sprays directly on the thermostat.
• Power cycle: With the thermostat removed, turn the breaker OFF for 2 minutes, then ON. Reinstall the thermostat and check if the E9 code and unresponsiveness clear.
• Replacement: If the touchscreen remains unresponsive or only partially responds, the user interface assembly is defective. Replace the thermostat with a new Ruud EcoNet smart thermostat.