It's their job to replace faulty parts, install new units, and ensure that the work they do will last. A refrigeration technician will also spend some time answering their clients' questions and maintaining their stock levels of important parts. They repair, install and troubleshoot systems in residential and commercial settings, which include heating, ventilation and air conditioning (HVAC) units, refrigerated storage units, ice machines and beverage equipment. Their duties include inspecting and testing refrigeration systems, performing preventive maintenance, and installing components such as compressors and control valves. They also operate and repair equipment like water processors, fire systems, and air compressors.