Performed maintenance on a three-zone A/C and heating system. Inspected and cleaned the condenser coils and evaporator coils for each zone to ensure efficient heat exchange. Checked refrigerant levels and adjusted as needed. Tested the blower motors and capacitors in all zones and lubricated moving parts. Verified that the thermostats for each zone were calibrated correctly. Ensured that the heating components were functioning properly by inspecting and cleaning the burner assemblies and heat exchangers. The system was tested to confirm all zones were operating efficiently and providing consistent comfort.