An E02 error on the Smart AC Control indicates an issue with the Wi-Fi connection.
To fix this, please do the following:
Make sure that your Wi-Fi is activated and working. To do so, check Wi-Fi access on other devices or the LEDs on the front of your router.
Check whether the Wi-Fi password has been changed. If this is the case, you can delete the current network data and connect your Smart AC Control to a new network.
If the issue persists, check the distance between your Smart AC Control and your router. If needed, move the device closer to the router. This will ensure that the Wi-Fi signal is strong enough.
Please note: when the internet connection is temporarily lost, you can control your AC via the user interface on the Smart AC Control. You can also use your old AC remote for this.