After not being able to locate any leaks, I got another dye set (this time UV) and loaded up the system again. Funny thing is, it stayed cold, I even took my dog to the vet and back this morning and it was nice and frosty in there! It's hot here, too!

So I was a bit hopeful it may have "corrected" itself, but alas, no. I went to get some take out BBQ tonight, and it was not cold at all. So at least I was able to run the system for about an hour and a half with it working. The dye should be well circulated, and when the sun goes down tonight, I'll have another look!