There are many reasons why your Truma air conditioner may not respond to commands from the remote control:
Check whether there are any obstructions between the remote control and the IR receiver.
You may need to first tune the remote control with the IR receiver or repeat this process. To do so, proceed as follows:
1. Insert the batteries into the remote control, observing the polarity.
2. The set-up symbol (1) flashes in the top-left corner of the remote control display. If this does not happen, press the reset button (2).
3. Aim the remote control at the IR receiver.
4. Press and hold the set-up button (3).
5. Release the set-up button once the red LED on the IR receiver of the Truma air conditioner flashes.
6. The remote control is now tuned with the IR receiver. The set-up symbol on the remote control disappears and the air conditioning system starts in circulation mode, with a low fan setting and no timer set.