Thermostat EFIT 540/550 is able to 
use two sensors, one built-in sensor 
plus an external sensor which can be 
placed e.g. in the fl oor.
Choose the sensor(s) which will be 
used for this heating system.
Turn to choose Room Sensor (r S), 
Floor Sensor (FS) or both Room and 
Floor Sensor (rFS), and press ...
(If the thermostat only uses a fl oor 
sensor, the display will not show the 
actual temperature (5º to 35º), but a 
scale from 0 to 10).
Always use a fl oor sensor when the 
heating element is installed on or be-
neath wooden surfaces !
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