Most vacuum/pressure switches cost between $25-$65 and can be
installed in 15 minutes or less.  Total Job:  $75 - $125
switches open and close a circuit whenever the switch
detects a vacuum generated by the draft inducer motor.

Some switches must prove they are open before the furnace
begins its ignition sequence and then will pull shut when the
vacuum has been established.

They are generally very easy to install.  Most are easily
accessible.  However, due to the wide variety and pressure
ratings for each switch, it is very possible the part will have to
be ordered or at the very least the technician will have to
pick one up at the supply house so travel time must be
factored into the total cost
Phone: (757) 506-6488