# Thermostat extension

Press the button to control an external KNX room thermostat. The push button's configured button then functions as an extension of the thermostat and can change its basic configurations (setpoint operating mode, switch from mode to cooling mode and vice-versa, presence detection).

#Caution

However, the thermostat extension is not actively involved in the actual calculation for the thermostat. It only works properly when all communication objects are linked to the appropriate objects in the associated KNX thermostat via a group address.