Steamfitter Service Technicians keep the equipment operating that heats and cools our buildings and homes and refrigerates our food. They install, maintain, and repair complex air conditioning and heating systems as well as other mechanical components in commercial buildings, and special industrial process applications. They must be able to trouble-shoot, diagnose and repair all of the components of an HVAC, or mechanical process system; compressors, condensers, metering devices, evaporators, air handling units, electronic controls and pneumatic controls.