Was a direct replacement of my old one. Worked perfect!. Did not have to make any adjustments. Just swapped the unit out. The original problem I had with my old controller is that it would not turn on my blower in the furnace unit that circulates air in the home. Probably a bad relay within the unit that would wear out over time., My unit is about 20 years old. I am sure this controller will last another 20 years.