I have a Trane heat pump, TWR060D100A1, Weathertron Heat Pump XE1000, with gas auxilliary backup. I want to adjust the outside temp sensor that communicates when the aux heat should come on and help the heat pump. I've removed the panel and see a knob that says C2 but I really have no idea if that's it or not, nor which way to turn it or see what it's currently set on. Any suggestions? It's cold here and I had our gas turned off for the summer, but got cold here before I thought it would so...want the heat to work at a lower temp without needing the aux.