Temperature out of range
When the room temperature is out of range, i.e. above 49 °C or below 0 °C, the temperature is displayed and flashes at "0 °C" or "49 °C", and the thermostat does not have any relay output.
Sensor error
"Er1" is displayed when the internal sensor does not work properly.
"Er3" is displayed when the external sensor is missing or does not work properly.
TOUCH IC error
"Er2" is displayed upon an error in the internal TOUCH IC.