What are you going to do with them if you find them?
Pressure switches are either good or no good...there is no in between & they rarely fail even if it says so in your book. So your problem is likely to lie elsewhere.
J3 refers to a plug port on the PCB. If you want to see where the pressure switch lives take off the lid & look for a brown circular plastic device with leads on the top & a black rubber hose on the side (or bottom depending on the type). Unless you are familiar with these devices all you'll be able to do is look at it.
BTW...F08 points to a possible heater relay problem.
Mike
November 2009