My furnace won't stay running. The inducer motor kicks on but then shuts off. The control board light flashes 3 times telling me the pressure switch failed to close. I cleaned the hose and replaced the pressure switch since it was about 13-14 y/o. I also cleaned the opening to the inducer motor. I'm still having problems with the pressure. The inducer comes on and off now while the furnace is running and I'm getting the 3 flashes on the control board again.
