First: turn remote control off if it is on (press start/stop button )
Second: hold down the temp up button down for 5 seconds then release, when released an f° should appear on the screen press the temp up button just once and it should change to a c°.
Third: once changed to c° press the start/stop button to turn the remote control on, the temp should now be displayed in c° not f°.
If this does not work, please contact our technical support team during AEST business hours on 1300 364 484.