I have a Goodman GMP075-3 RevB. The fan for the exhast comes on but the starter does not heat up and the burners do not go on. Light blinks 3 times. This means the Venter Pressure switch vent is blocked. What does that mean? There is a rubber hose on the exhast fan that when I blow into it, I cannot get any air through. I do not know how to remove this from the fan.

One end of the rubber tube hooks to the pressure switch and the other to the collecter box. Did you check to make sure you did not have a restriction at the connection on the collector box?