Hmm...I rewired my flexwatt just to see if something is wrong with that. My differential is set to 1, I meant to write that.... Now that it's rewired and the probe is retaped to my flexwatt, it's set at 88 and reading 86 on the Ranco. I don't get it.... I guess I'll just have to plan for that 2 degree difference and set it 2 degrees higher than I actually want? It has yet to reach the desired temp, so it hasn't shut off from it getting hot. I took the probe off and it's now in the the tank (for a GTP). We'll see what happens I guess!
Thanks for the help guys, hopefully I'll get it figured out.
Oh and I have every digital thermometer I have in the house in the tank. The stupid Ranco says it's 78, but all my thermometers say 74.3-75, I'll have to keep a close eye on that, and maybe move the probe to the very top of the tank, as far away from the flexwatt as possible.