Diagnose and repair malfunctions in various types of HVAC and commercial food service equipment and appliances including, but not limited to, coolers and freezers, food cookers, heaters and warmers, all oven types, dishwashers, food waste disposers, mixing and cutting equipment, ice machines, clothes washers and dryers, exhaust ventilation systems, heat exchangers, boilers, air conditioning and heating systems, and chillers. Environment: Work outside and inside, on slippery or uneven walking surfaces; may work on rooftops; frequent exposure to extreme hot and cold temperatures, dust, toxic chemicals and materials, noise, vibration, and electrical hazards; work around machinery with moving parts; may work in tight or enclosed spaces; may work alone; may work irregular and prolonged hours; frequent districtwide travel.