I wrote support about the issue with the wifi connection and a month later I heard back from a Mr. Cool support person. There are two different wifi control apps available for iPhones, one is Mr. Cool and the other is SmartHVAC. Being a somewhat technical person I of course tried both and the dongle is found with either one on the wifi network but neither app recognizes it and freezes or gives an error message.
When tech support contacted me I had to give them the information about the install, the messages I was getting etc. They said with the type of dongle I had the app to use was SmartHVAC. So I reinstalled that and discarded Mr. Cool. I then went through the entire process again for support. I sent them the error message and waited for a response.
When I didn’t hear back in a day or two I wrote and asked for a new dongle. The response was to send the serial number, place of purchase, name, address, and phone. I responded in the old text and it was received with no information so I had to do it again. Although they never wrote to tell me the new dongle had been shipped, in a week or two I received a box with another dongle.
I climbed up to the unit and replaced the old one and followed instructions to delete and reinstall the application. At first even though I put the unit in receiving mode, I got the same error message but when I tried again I was able to continue the setup from this point. All it had me do was choose the home router and enter the password and I was able to use the application.
Success! But the weather has turned cool and I won’t need the air conditioning until next summer!