ESSENTIAL DUTIES - May include, but not limited to the following: Conduct routine preventive maintenance on equipment, including: air handlers, rooftop units, chillers, boilers, pumps, VAV boxes, split systems, and related controls. Under HB 558, enacted by the 76th Texas State Legislature, if you are currently of the age and gender requiring registration with Selective Service, but knowingly and willfully fail to do so, you are ineligible for employment with an agency in any branch of Texas state government.