I have a model M1B077A-Aw Miller furnace that is telling me through an indicator light that the pressure switch is open.I'm guessing that this will cause the unit to not turn on.How do I solve this issue,just short of replacing the pressure switch completely?

The only thing I can tell you is if there is a problem with the pressure switch you will have to replace it. Only nice thing they are easy to replace. Good luck hope this helps