Repairing or replacing defective parts in units and equipment and their controls, including thermostats, automatic switches, fan controls, log switches, damper motors, louvers, relays, filters, controls, belts, compressors, heat exchangers, high limit controls, pressure controls, safety valves, and automatic gas valves. This role performs skilled electrical and mechanical maintenance duties in the inspection, repair, installation, and alteration of commercial heating, ventilation, air conditioning, and refrigeration (HVACR) systems and related equipment and facilities.