Check a/c unit operation Believe universal board is flagging a false low pressure lockout. Pressures look good in heating and cooling modes. Have model and serial to replace board. 20 degree delta T. Customer would like to start a PCSA when I come back so please allow time for repair and full maintenance. 3/24 unit is looking good board replacement went great all checks good on maint filter replaced coil cleaned drain flushed clean out added to drain line