Clean drain. Changed filter. Checked all electronic components. Checked amps on blower motor and heat strip. Both tests fine. Test zone dampers. both dampers working as they should. Checked amps on compressor and fan. Checked pressures on condenser on outside. High-pressure switch was shutting the unit down. Pressures running 140 and 550. Manufacture pressure should be 120/390. Let refrigeration out to get to manufacture pressure. Heat pump performance as it should.