Some customers find it helps to turn off the 5GHz Wi-Fi from the Hub 5 for a period just leaving the 2.4GHz band running, this ensures your mobile and the 2.4GHz A/C unit will be on the same Wi-Fi band during the setup process.
This may not work as the pods require both bands I believe and you are trying to connect to one of them. The best long term solution I can think of is to buy a cheap Wireless Access Point, wire it into the hub, disable the 5Ghz band, set the SSID name different from the hub and then connect to this new SSID. Just during the set up of the ac/heat pump you may have to join this new SSID on your phone, but afterwards you can forget it on the phone.
