Duties may include but are not limited to the following: Inspects and diagnoses, operates, maintains, repairs, installs and performs major overhauls to heating, ventilation, air conditioning and refrigeration systems and equipment, including but not limited to boilers, chillers, air handlers, air purifiers and scrubbers, cooling towers, heat exchangers, mixing boxes, furnaces, hot water heaters, pumps, valves, piping, ducting, control and chemical treatment systems, and similar equipment. The examination process may consist of the following: Written Exam 100%: A job-related written examination may be administered which may test a candidates knowledge in the following areas: terminology, operation, and maintenance and repair of heating ventilation and air conditioning units, water supply, pumps and wells, tools and safety, water mains and services, public relations, interpersonal skills, mathematics, and reading comprehension.