You sure the gauge is right ? For a 2 story you need about 18psi on the boiler. Back the lock nut off some and turn slow and just a small amount at a time .turn CW for more psi . You should have to kick up the psi till you just get water out of the top bleeder is all. Dont run the pump when you do this and do it slow slow.
ED
My mistakes dont define me they inform me.