How I freed a pool heat pump from an unencrypted Chinese cloud server

I have a pre-installed pool heat pump - an “AcquaSource” branded unit, the kind you can buy at any pool store in Europe - which supports WiFi. The App called “Pool Panel” wasn’t pretty, but it worked and I didn’t give it much thought. At one time, the remote control of the pump stopped responding: The pump itself was fine; the panel worked, the temperature held. So I decided to take a deeper look…