Most large office buildings, malls, warehouses, and other commercial facilities have extensive heating, ventilation, and air-conditioning systems that keep them comfortable all year long. Industrial plants often have additional facilities to provide electrical power, steam, or other services. Stationary engineers and boiler operators control and maintain these systems, which include boilers, chillers, air-conditioning and refrigeration equipment, diesel engines, turbines, generators, pumps, condensers, and compressors. The equipment that stationary engineers and boiler operators control is similar to equipment operated by locomotive or marine engineers, except that it is used to generate heat or electricity rather than to move a train or ship.
Stationary engineers and boiler operators start up, regulate, repair, and shut down equipment. They ensure that the equipment operates safely, economically, and within established limits by monitoring meters, gauges, and computerized controls. When necessary, they control equipment manually and make adjustments using hand and power tools. They watch and listen to machinery and routinely check safety devices, record data in logs, and identify any potential problems.
Routine maintenance is a regular part of the work of stationary engineers and boiler operators. Engineers use tools to perform repairs ranging from a complete overhaul to replacing defective valves, gaskets, or bearings. They lubricate moving parts, replace filters, and remove soot and corrosion that can reduce the boiler's operating efficiency. They also test the water in the boiler and add chemicals to prevent corrosion and harmful deposits.
In most facilities, stationary engineers are responsible for the maintenance and balancing of air systems, as well as hydronic systems that heat or cool buildings by circulating fluid (such as water or water vapor) in a closed system of pipes. They may check the air quality of the ventilation system and make adjustments to keep the operation of the boiler within mandated guidelines. Servicing, troubleshooting, repairing, and monitoring modern systems all require the use of sophisticated electrical and electronic test equipment.
In a large building or industrial plant, a senior stationary engineer may be in charge of all mechanical systems in the building and may supervise a team of assistant stationary engineers, turbine operators, boiler tenders, and air-conditioning and refrigeration operators and mechanics. In small buildings, there may be only one stationary engineer who operates and maintains all of the systems.
Stationary engineers and boiler operators held about 30,700 jobs in 2020. The largest employers of stationary engineers and boiler operators were as follows:
- Manufacturing - 20%
- Hospitals; state, local, and private - 18%
- Educational services; state, local, and private - 17%
- Local government, excluding education and hospitals - 10%
- State government, excluding education and hospitals - 8%
In a large building or industrial plant, a senior stationary engineer or boiler operator may be in charge of all mechanical systems in the building and may supervise a team of assistant stationary engineers, assistant boiler tenders, and other operators or mechanics.
In small buildings, there may be only one stationary engineer or boiler operator who operates and maintains all of the systems.
Some stationary engineers and boiler operators are exposed to high temperatures, dust, dirt, and loud noise from the equipment. Maintenance duties may require contact with oil, grease, and smoke.
Workers spend much of their time on their feet. They also may have to crawl inside boilers and work while crouched, or kneel to inspect, clean, or repair equipment.
Injuries and Illnesses
Stationary engineers and boiler operators risk injury on the job. They must follow procedures to guard against burns, electric shock, noise, dangerous moving parts, and exposure to hazardous materials.
Most stationary engineers and boiler operators work full time during regular business hours. In facilities that operate around the clock, engineers and operators may work either one of three 8-hour shifts or one of two 12-hour shifts on a rotating basis. Because buildings such as hospitals are open 365 days a year and depend on the steam generated by boilers and other machines, many of these workers must work weekends and holidays.
Education & Training Required
Most employers prefer to hire people with at least a high school diploma or the equivalent for stationary engineers and boiler operator jobs. Workers acquire their skills primarily on the job and usually start as apprentices or helpers. This practical experience may be supplemented by postsecondary vocational training in subjects such as computerized controls and instrumentation. Becoming an engineer or operator without completing a formal apprenticeship program usually requires many years of work experience.
The International Union of Operating Engineers sponsors apprenticeship programs and is the principal union for stationary engineers and boiler operators. Apprenticeships usually last 4 years and include 6,000 hours of on-the-job training. Apprentices learn to operate boilers, generators, compressors, motors, and air-conditioning and refrigerating equipment.
Apprentices also receive 600 hours of classroom instruction, studying elementary physics, practical chemistry, blueprint reading, instrumentation, and other technical subjects.
Continuing education—such as vocational school or college courses—is becoming increasingly important for stationary engineers and boiler operators, in part because of the growing complexity of the equipment with which engineers and operators now work.
Most large and some small employers encourage and pay for skill-improvement training for their employees. Training is almost always provided when new equipment is introduced or when regulations concerning some aspect of the workers' duties change.
Many State and local governments have licensing requirements for stationary engineers and boiler operators. Applicants for licensure usually must be at least 18 years of age, reside for a specified period in the State or locality in which they wish to work, meet experience requirements, and pass a written examination. A stationary engineer or boiler operator who moves from one State or city to another may have to pass an examination for a new license because of regional differences in licensing requirements.
There are generally four or five classes of stationary engineer licenses. Each class specifies the type and size of equipment the engineer is permitted to operate without supervision. A top-level stationary engineer is qualified to run a large facility, supervise others, and operate equipment of all types and capacities. An applicant for this license may be required to have a high school education, have completed an apprenticeship or lengthy on-the-job training, and have several years of experience working with a lower class license. Engineers with licenses below this level are limited in the types or capacities of equipment they may operate without supervision.
Many job openings require that workers be licensed before starting the job, although some jobs may offer apprenticeships.
Other Skills Required
In addition to training, stationary engineers and boiler operators need mechanical aptitude and manual dexterity. Most employers of entry-level workers and apprenticeship committees prefer applicants with a basic understanding of mathematics, science, computers, mechanical drawing, machine shop practice, and chemistry. Being in good physical condition is also important.
How to Advance
Generally, engineers advance as they obtain higher class licenses. These licenses permit boiler operators to work with larger, more powerful, or more varied equipment. In jurisdictions where licenses are not required, workers generally advance by taking company-administered exams. Some stationary engineers and boiler operators advance to become boiler inspectors, chief plant engineers, building and plant superintendents, or building managers. A few obtain jobs as examining engineers or technical instructors.
Because most stationary engineering staffs are relatively small, workers may find it difficult to advance, especially within a company. Most high-level positions are held by experienced workers with seniority. Workers wishing to move up to these positions must often change employers or wait for older workers to retire before they can advance.
Employment of stationary engineers and boiler operators is projected to grow 6 percent from 2020 to 2030, about as fast as the average for all occupations.
About 4,000 openings for stationary engineers and boiler operators are projected each year, on average, over the decade. Many of those openings are expected to result from the need to replace workers who transfer to different occupations or exit the labor force, such as to retire.
Steam is an important and cost-effective way to fuel machinery and to provide utilities in large facilities. Workers will be needed for routine maintenance and to ensure that the equipment is working properly.
The median annual wage for stationary engineers and boiler operators was $63,500 in May 2021. The median wage is the wage at which half the workers in an occupation earned more than that amount and half earned less. The lowest 10 percent earned less than $44,260, and the highest 10 percent earned more than $100,690.
In May 2021, the median annual wages for stationary engineers and boiler operators in the top industries in which they worked were as follows:
- Local government, excluding education and hospitals - $97,570
- Hospitals; state, local, and private - $74,300
- State government, excluding education and hospitals - $72,890
- Educational services; state, local, and private - $61,080
- Manufacturing - $60,910
Most stationary engineers and boiler operators work full time. In facilities that operate around the clock, engineers and operators may work either one of three 8-hour shifts or one of two 12-hour shifts on a rotating basis. Because buildings such as hospitals are open 365 days a year and depend on the steam generated by boilers and other machines, many of these workers must work weekends and holidays.