Evacuate, drop charge all works but trips on HP after about 30 min. Start up again and observe pressures. Had to drop about 750 grams out of unit and it works like a dream. Works a treat on heat, as a piece of York **** does, but not as good on cool, but that is the York design.
Thanks for the update.
Not going to say I told you so...but not sure you got it "fixed" either, unfortunately. I'm afraid you'll be back in the cooling season adding refrigerant.
It sounds like if you had checked your low side pressure in heating (even if you only have 4 min of operation) you could have seen that there was an obvious restriction and saved yourself many, many hours of wasted time. The problem isn't with York equipment, it sounds like it was with the installer.
I was going to suggest clogged or wrong size acurator. Older York heat pumps used to use a TXV on the condenser to meter the refrigerant in heat mode. I ran into many of those that were restricted and the unit would do the exact same thing you described, trip on high pressure after 10 to 15 minutes of operation. York discontinued the TXV's on outdoor units and they give you an acurator kit to emiminate the faulty TXV.