I have a goodman furnace.. I replaced the thermostat.. that was'nt the problem.. my heat won't come on by itself.. my husband has to go in the basement and unplug the air pressure switch.. it will then run for about 1/2 day.. then, he has to do it again.. we think it is the air pressure switch, but we are not sure.. does anyone know what we can do?

Not uncommon for a pressure switch to stick. 80% or 90% gas furnace? If it's a 90% furnace (vented with PVC) check the condensate drain it may have a restriction and will not let the pressure switch close. On a 90% furnace the pressure switch will not close if the drain line,vent pipe and or intake pipe is restricted. On a 80% furnace more or less the pressure switch is checking the vent for restriction.

Can you help me.. I want to remove the circuit board cover.. how do I do this? My furnace is in the basement.. it is very hard to see.. I don't want to jerk/pull the cover off, and break it.. is there screws that I'm not seeing? Thank you so much for your helpm with my original question.. I will check the pressure switch for sticking.. also, do you know where I could buy a replacement air pressure switch? Goodman website has $269.00.. I'm looking for much cheaper if possible.. thanks again..

The circuit board cover is held on by screws. Is the pressure switch on the vent pipe out side of the furnace or mounted inside the furnace? Are you asking how to remove the circuit board cover or lower door on furnace?