Electra Central AC
Electra Central AC Smart WiFi Controller v4
Electra Central AC Smart WiFi Controller v5
The connection to the MQTT server used to control the AC over the Internet uses a password that is hardcoded into the firmware (i.e., it’s shared between all the units and can be easily obtained).
On top of that, the firmware on these versions (v4/v5) of the units is not updateable, so changing the password on the server without breaking functionality is not possible.