Thermostat display is on but does not respond to button presses or touchscreen taps.

Safety first: Remove power (batteries or mains) before opening the thermostat.

• Power-cycle: Remove batteries or isolate mains for 30 seconds, then restore power to reboot the thermostat.
• Clean around buttons: For physical buttons, gently clean around them with a dry brush to remove dust or debris that may be jamming the mechanism.
• Check for screen damage: Inspect the touchscreen for cracks or impact damage. A cracked digitiser will often cause dead zones.
• Reseat internal connectors: If accessible, reseat the keypad or touchscreen ribbon cable on the PCB.
• Replace front module: If the UI remains unresponsive, replace the thermostat front module, as keypad/touchscreen components are not usually serviceable.