Ok, so it is my first install of a GoodMan gas furnace & evap cabinet, and I believe it has a white rodgers control board?!?! well anyway, I finished the install and went to test the cooling. Everything went fine! Heat is a different story.I guess after wondering for about 1 1/2 hours why the unit cools but doesnt heat I called a supervisor, he came and told me that the gas valves will not run if the polarity of the current is reversed, the circuit board ceases to operate the heat.
Can anyone explain to me why reversing the polarity affects the furnace in that way?