You can lock the Infinity
™ Control buttons to help avoid inadvertent
changes to your settings.
Keyboard lock-out can ONLY be activated from the main screen.
To do so, simultaneously press the ZONE and FAN buttons for two
seconds. Keyboard lock-out will be indicated by a graphic lock on
To unlock the control, simultaneously press the ZONE and FAN
buttons for two seconds.
That's to lock and unlock it. Not sure if you can actually disable the feature. Check inside the stat to see if there is a removable jumper labelled "lock".