Temperature out of range
When the room temperature is outside the measuring range, i.e. above 49 °C or below 0 °C, the temperature value will blink at the limit values, i.e. "0 °C" or "49 °C". After the temperature returns to within the measuring range, the thermostat will continue to work.
For heating application, the heating output will be turned on when the temperature drops below the limit value, provided the Protection mode setpoint is not set to Off.
The cooling output in cooling applications will be turned off when the temperature exceeds the limit value, provided the Protection mode setpoint is not set to Off.
No output is activated if protection mode setpoint is set to Off.
Fault “Er1” on display
When the built-in sensor fails and no external sensor is connected, the thermostat shows the fault message “Er1” on the display. The thermostat needs to be replaced.
When the internal non-volatile memory has error, e.g. unable to read or write, the thermostat shows the fault message “Er2” on the display. If it is only data corruption in the memory, a master reset can fix this error. Otherwise, the thermostat is defective and need to be replaced.
When the external sensor is selected for floor temperature limitation (P51 ≠ OFF) and is not working properly, e.g. faulty or sensor is missing, the thermostat shows the fault message “Er3” on the display.
The heating output turns off immediately to ensure safety and avoid overheating of the floor. The room temperature measured by internal sensor continues to be shown on the LCD display.
1) Er1 has a higher display priority than Er2.
2) Once the external sensor fault is removed, the thermostat returns to normal working mode.
For fault status messages on the bus, see section 3.11.8.
In the event of a power failure, all working conditions (operating mode, setpoint, fan stage, all control parameter settings) are stored without time limitation.
When power returns, the thermostat reloads this data and continues to work in the same conditions as before.