You can also check the address code on the Hydro-X as shown below :
3. FAN Setting
Press FAN button to select ON or AUTO (toggle to re-select) mode for the fan
inside an air-conditioner.
AUTO : Fan runs only when the heating or cooling system is on. Auto is the
most commonly used setting.
ON : Fan is always on.
NOTE : Options may vary depending on your heating/cooling equipment.