What Does a Stationary Engineer Do?
The steady supply of heat, cooling, and backup power for hospital wards, research labs, and residence halls often comes from a central plant. Stationary engineers run that plant, and the job is distinguished from a boiler operator's in that it covers chillers, cooling towers, compressors and generators as well as boilers.
Also known as: Senior Stationary Engineer
Stationary Engineer Duties and Responsibilities
The primary responsibilities of a stationary engineer include:
- Operate boilers, chillers, cooling towers and air compressors from the central plant control room.
- Start and stop plant equipment in sequence to match campus heating and cooling loads.
- Record readings from gauges, meters and the plant control system on every shift.
- Treat cooling tower water to control scale and bacteria such as Legionella.
- Overhaul pumps, valves, heat exchangers and chiller components during scheduled shutdowns.
- Run emergency generators under load and keep their fuel, batteries and logs in order.
- Tune plant setpoints and equipment staging to cut fuel and electricity use.
- Keep environmental records, such as emissions logs and chemical inventories, ready for audits.
- Direct operators and apprentices on shift, and step in when alarms or trips occur.
- Walk steam tunnels and building mechanical rooms to find leaks and failing equipment early.
Required Skills and Qualifications
To succeed as a stationary engineer, you will need the following skills and qualifications:
- Stationary engineer license where the state or city requires one
- Chiller, boiler and cooling tower operation
- Plant control systems and trend data
- Mechanical repair of pumps, valves and compressors
- Water treatment chemistry
- Electrical basics for motors and generators
- Leadership on a shift crew
- Level-headed response to trips and alarms
Education and Training
Once you have a few years in a plant as an operator or mechanic you will need to pass the stationary engineer license exam, where your state or city requires one. Many engineers start after high school through a union apprenticeship, such as those run by the International Union of Operating Engineers. License grades rise with experience.
Salary and Job Outlook
Typical pay: $63,160 - $101,150 per year, with a median of $78,620.
The range covers the middle half of earners nationwide. Source: U.S. Bureau of Labor Statistics, Occupational Employment and Wage Statistics, May 2025, Stationary Engineers and Boiler Operators.
According to BLS, employment of stationary engineers and boiler operators is projected to grow about 3 percent from 2025 to 2035. That is slow growth in a small field of roughly 3,200 openings a year, so plants often fill senior posts by promoting their own operators. Given that plants keep adding digital controls and energy targets, engineers who can read trend data as well as a pressure gauge are more likely to move up.
Outlook source: U.S. Bureau of Labor Statistics, Employment Projections, 2025 to 2035, Stationary engineers and boiler operators.