today is dec. 27 2013 - I also own a Carrier 58SS-100. I am tired of paying to HAVC people that don't "look beyond the box", such as a dead bird on the piper, causing the pressure switch to go criase. My next step to fix my pressure switch or my Control Board will be, first, check if the my pipes without obstruction. thank you, good luck, save you money, learn by doing it yourself. and what pleasure it gives when you can say, I save myself $300.00 box.