Stationary Engineer

A stationary engineer runs and maintains the boilers, chillers, generators, and HVAC systems that keep a large building or plant operating — monitoring gauges and controls, adjusting the equipment to match the load, and doing the repairs and water-treatment that keep it efficient and safe. They hold the licenses that high-pressure and refrigeration systems require, and they're often the ones on site when something fails in the small hours.

They work in hospitals, universities, office towers, and industrial plants, typically on shifts. The role suits steady, methodical people who are comfortable with complex mechanical systems and the responsibility of keeping critical building services running.