RT520 Series Boiler Plus Compliant Thermostat | 7.2. Common Issues | Hilfecenter
2. Heating not following schedule times.
Where are the batteries ?
1. Hand Symbol on Screen
3. Snowflake Symbol on Screen
How do I remove the thermostat from the wall ?
High pitched whine or fast clicking sound from thermostat.
Switching off the Service Mode warning.
Screen backlight randomly turning on and flattening batteries.
Thermostat randomly turns heating up or down on its own.