Gator if you are seeing swings that is almost always caused from the LHT not being set high enough. Once the unit is at set point if the LHT is high enough it should never go back into the HHT which is what causes the swings. I would recommend leaving the HHT at the default and raise your LHT to 20. If you still get swings raise it a little more. I have attached a sheet that goes over the theory in out control system to help as well. give Cookshack a call if you need any assistance dialing it in.