Troubleshoot and repair air conditioning units, electric heating units, gas heating units, waste oil heaters such as changing filters, lighting pilots, replacing compressors, fans, switches, Freon, metering valves, and other similar repairs. Perform preventative maintenance on air compressors, including changing oil and filters and checking gauges, pressures and amp draw; Make repairs to air compressors, including replacing electric motors, seals, gages, motor controls, and other similar components.