HVAC Service 2023 PCSA Heating Check Up Prepaid Heating Maintenance System was 3 lbs low on R-410A upon arrival. System needs a leak search when possible. Checked wire connections. Replaced filter. Relays on heater package are making a loud buzzing sound during operation. Recommend replacing under warranty. 2-1-24: Performed leak search and identified two out of three shcrader cores were leaking. Repaired both and verified they were no longer leaking. Checked charged and verified it was still holding. Pressures and subcooling are acceptable. System is operating efficiently at this time.