Troubleshoot, repair, and perform preventive maintenance on boilers, hot water heaters, pumps, valves, piping, filters, and variable frequency drives (VFDs) on HVAC units and pumps, analyzing system operations to determine root causes of malfunctions and implementing corrective actions. Install, repair, and maintain electrical controls, motor controls, switching systems, and associated mechanical equipment including wiring single and three-phase motors, running conduit, and rebuilding pumps, motors, and air compressors.