Stationary Engineers and Boiler Operators
Stationary Engineers and Boiler Operators (SOC 51-8021) earn a median $78,620 a year ($37.80 an hour) in the United States, with 28,250 employed as of May 2025; the highest-paying state is Illinois.
What stationary engineers and boiler operators do
Stationary engineers and boiler operators run the equipment that supplies heat, steam, power, and cooling to buildings and industrial processes. Their plants contain boilers, engines, turbines, generators, pumps, compressors, and air-conditioning systems. Throughout a shift, the operator watches gauges, meters, and charts, opens and closes valves to hold the right water level in the boiler, and adjusts combustion air and fuel flow. Water and chemical levels are tested and corrected. When readings drift or a problem appears, the engineer analyzes it and takes action to keep service reliable. Daily logs record readings, tests, maintenance work, and any malfunctions. The operator tests boiler water quality, or arranges testing, and adds chemicals to prevent corrosion and harmful deposits. This work differs from that of power plant operators, who are classified separately and whose purpose is generating electric power.
Typical entry: According to O*NET, a post-secondary certificate is the most common level of education reported by workers in this occupation.
Also called: Air Compressor Engineer, Air Compressor Operator, Air Conditioning Engineer (AC Engineer), Air Plant Engineer, Auxiliary Operator.
National wage percentiles, May 2025
| Area | Basis | Percentile wage | Mean | Employment | ||||
|---|---|---|---|---|---|---|---|---|
| 10th | 25th | Median | 75th | 90th | ||||
| United States | Hourly | $24.32 | $30.37 | $37.80 | $48.63 | $60.28 | $40.37 | 28,250 |
| Annual | $50,590 | $63,160 | $78,620 | $101,150 | $125,390 | $83,960 | ||
Employment per 1,000 jobs and the location quotient are area measures; they appear in the state and metro tables below. To see what a wage in this range leaves after tax, use FastCalc's take-home pay calculator.
Where stationary engineers and boiler operators earn and work most
Five highest-paying states
| Area | Basis | Percentile wage | Mean | Employment | Jobs per 1,000 | Location quotient | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| 10th | 25th | Median | 75th | 90th | ||||||
| Illinois | Hourly | $34.74 | $41.71 | $55.66 | $59.51 | $60.22 | $51.16 | 1,680 | 0.28 | 1.52 |
| Annual | $72,270 | $86,750 | $115,780 | $123,780 | $125,260 | $106,410 | ||||
| Wyoming | Hourly | $30.26 | $53.59 | $53.81 | $54.80 | $55.86 | $49.28 | 100 | 0.36 | 1.98 |
| Annual | $62,940 | $111,480 | $111,920 | $113,980 | $116,180 | $102,500 | ||||
| Hawaii | Hourly | $27.75 | $40.45 | $49.71 | $50.76 | $54.16 | $45.47 | 70 | 0.11 | 0.59 |
| Annual | $57,720 | $84,140 | $103,400 | $105,570 | $112,660 | $94,580 | ||||
| Connecticut | Hourly | $32.46 | $39.55 | $45.61 | $48.84 | $52.73 | $44.23 | 270 | 0.16 | 0.87 |
| Annual | $67,520 | $82,250 | $94,870 | $101,580 | $109,680 | $91,990 | ||||
| New York | Hourly | $29.46 | $33.77 | $45.22 | $66.57 | $72.95 | $48.59 | 4,480 | 0.46 | 2.55 |
| Annual | $61,290 | $70,250 | $94,070 | $138,460 | $151,730 | $101,070 | ||||
Five states with the most jobs
| Area | Basis | Percentile wage | Mean | Employment | Jobs per 1,000 | Location quotient | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| 10th | 25th | Median | 75th | 90th | ||||||
| California | Hourly | $23.37 | $29.74 | $43.58 | $57.86 | $63.81 | $43.75 | 5,840 | 0.32 | 1.76 |
| Annual | $48,610 | $61,860 | $90,650 | $120,350 | $132,730 | $91,010 | ||||
| New York | Hourly | $29.46 | $33.77 | $45.22 | $66.57 | $72.95 | $48.59 | 4,480 | 0.46 | 2.55 |
| Annual | $61,290 | $70,250 | $94,070 | $138,460 | $151,730 | $101,070 | ||||
| Pennsylvania | Hourly | $23.15 | $30.04 | $35.05 | $38.30 | $42.79 | $34.13 | 1,730 | 0.29 | 1.57 |
| Annual | $48,140 | $62,490 | $72,900 | $79,670 | $89,000 | $70,990 | ||||
| Illinois | Hourly | $34.74 | $41.71 | $55.66 | $59.51 | $60.22 | $51.16 | 1,680 | 0.28 | 1.52 |
| Annual | $72,270 | $86,750 | $115,780 | $123,780 | $125,260 | $106,410 | ||||
| Minnesota | Hourly | $29.63 | $32.36 | $36.47 | $40.69 | $47.41 | $37.37 | 1,440 | 0.49 | 2.69 |
| Annual | $61,620 | $67,310 | $75,850 | $84,640 | $98,610 | $77,730 | ||||
Five highest-paying metropolitan areas
| Area | Basis | Percentile wage | Mean | Employment | Jobs per 1,000 | Location quotient | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| 10th | 25th | Median | 75th | 90th | ||||||
| San Francisco-Oakland-Fremont, CA | Hourly | $29.80 | $48.82 | $62.46 | $65.22 | $69.37 | $57.06 | 980 | 0.41 | 2.27 |
| Annual | $61,980 | $101,550 | $129,930 | $135,660 | $144,280 | $118,680 | ||||
| San Jose-Sunnyvale-Santa Clara, CA | Hourly | $30.76 | $41.54 | $59.22 | $71.29 | $77.29 | $56.74 | 210 | 0.19 | 1.04 |
| Annual | $63,990 | $86,400 | $123,170 | $148,280 | $160,750 | $118,020 | ||||
| Vallejo, CA | Hourly | $37.40 | $49.85 | $59.22 | $63.51 | $70.17 | $56.03 | 110 | 0.79 | 4.33 |
| Annual | $77,790 | $103,690 | $123,170 | $132,100 | $145,950 | $116,550 | ||||
| Springfield, IL | Hourly | $30.16 | $40.84 | $56.53 | $64.61 | $76.15 | $54.95 | 60 | 0.63 | 3.46 |
| Annual | $62,740 | $84,950 | $117,590 | $134,390 | $158,390 | $114,300 | ||||
| Chicago-Naperville-Elgin, IL-IN | Hourly | $37.66 | $46.89 | $55.66 | $59.51 | $60.22 | $52.98 | 1,210 | 0.27 | 1.48 |
| Annual | $78,320 | $97,540 | $115,780 | $123,780 | $125,260 | $110,200 | ||||
Five metropolitan areas with the most jobs
| Area | Basis | Percentile wage | Mean | Employment | Jobs per 1,000 | Location quotient | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| 10th | 25th | Median | 75th | 90th | ||||||
| New York-Newark-Jersey City, NY-NJ | Hourly | $31.01 | $38.23 | $50.39 | $69.00 | $73.23 | $51.97 | 3,810 | 0.40 | 2.21 |
| Annual | $64,500 | $79,510 | $104,810 | $143,530 | $152,330 | $108,100 | ||||
| Los Angeles-Long Beach-Anaheim, CA | Hourly | $23.50 | $27.50 | $35.78 | $50.95 | $57.28 | $38.58 | 1,980 | 0.32 | 1.73 |
| Annual | $48,880 | $57,190 | $74,420 | $105,970 | $119,130 | $80,250 | ||||
| Chicago-Naperville-Elgin, IL-IN | Hourly | $37.66 | $46.89 | $55.66 | $59.51 | $60.22 | $52.98 | 1,210 | 0.27 | 1.48 |
| Annual | $78,320 | $97,540 | $115,780 | $123,780 | $125,260 | $110,200 | ||||
| San Francisco-Oakland-Fremont, CA | Hourly | $29.80 | $48.82 | $62.46 | $65.22 | $69.37 | $57.06 | 980 | 0.41 | 2.27 |
| Annual | $61,980 | $101,550 | $129,930 | $135,660 | $144,280 | $118,680 | ||||
| Washington-Arlington-Alexandria, DC-VA-MD-WV | Hourly | $29.43 | $38.19 | $43.98 | $48.81 | $51.87 | $43.00 | 970 | 0.31 | 1.70 |
| Annual | $61,220 | $79,430 | $91,480 | $101,520 | $107,890 | $89,430 | ||||
Top industries employing stationary engineers and boiler operators
General Medical and Surgical Hospitals employ 17.8% of stationary engineers and boiler operators nationally (5,030 jobs) at a median $81,760 a year ($39.31 an hour), followed by Local Government, excluding Schools and Hospitals (OEWS Designation) (11.1%) and Colleges, Universities, and Professional Schools (9.5%).
| Industry | Employment | Share of occupation | Median annual | Median hourly |
|---|---|---|---|---|
| General Medical and Surgical Hospitals NAICS 622100 | 5,030 | 17.8% | $81,760 | $39.31 |
| Local Government, excluding Schools and Hospitals (OEWS Designation) NAICS 999300 | 3,140 | 11.1% | $106,580 | $51.24 |
| Colleges, Universities, and Professional Schools NAICS 611300 | 2,670 | 9.5% | $75,030 | $36.07 |
| State Government, excluding Schools and Hospitals (OEWS Designation) NAICS 999200 | 1,910 | 6.8% | $78,340 | $37.66 |
| Traveler Accommodation NAICS 721100 | 1,810 | 6.4% | $54,880 | $26.39 |
Share is the industry's employment over the occupation's national employment (28,250). Industries whose employment BLS withheld are not ranked.
Published medians, May 2021 to May 2025
BLS published a median annual wage of $63,500 for stationary engineers and boiler operators in May 2021 and $78,620 in May 2025, with employment of 29,820 and 28,250.
| Release | Median annual | Median hourly | Employment |
|---|---|---|---|
| May 2021 | $63,500 | $30.53 | 29,820 |
| May 2022 | $67,120 | $32.27 | 31,470 |
| May 2023 | $67,640 | $32.52 | 33,840 |
| May 2024 | $75,190 | $36.15 | 30,780 |
| May 2025 | $78,620 | $37.80 | 28,250 |
BLS does not design OEWS as a time series: each release pools three years of samples, and occupational classifications, area definitions and estimation methods change between releases, so a difference between two releases is not a measure of change over time. The figures are shown as published, side by side, and nothing is computed from them. See how often OEWS is updated.
Every state, by median wage
51 states and DC publish a row for this occupation. A linked state has its own page with the within-state metro table and comparison; the others appear here only.
| Rank | State | Median hourly | Median annual | 10th pct (annual) | 90th pct (annual) | Employment | Jobs per 1,000 | Location quotient |
|---|---|---|---|---|---|---|---|---|
| 1 | Illinois profile | $55.66 | $115,780 | $72,270 | $125,260 | 1,680 | 0.28 | 1.52 |
| 2 | Wyoming profile | $53.81 | $111,920 | $62,940 | $116,180 | 100 | 0.36 | 1.98 |
| 3 | Hawaii profile | $49.71 | $103,400 | $57,720 | $112,660 | 70 | 0.11 | 0.59 |
| 4 | Connecticut profile | $45.61 | $94,870 | $67,520 | $109,680 | 270 | 0.16 | 0.87 |
| 5 | New York profile | $45.22 | $94,070 | $61,290 | $151,730 | 4,480 | 0.46 | 2.55 |
| 6 | Washington profile | $44.00 | $91,530 | $67,220 | $128,250 | 520 | 0.15 | 0.80 |
| 7 | California profile | $43.58 | $90,650 | $48,610 | $132,730 | 5,840 | 0.32 | 1.76 |
| 8 | District of Columbia profile | $43.50 | $90,470 | $62,710 | $108,600 | 620 | 0.89 | 4.89 |
| 9 | Alaska profile | $42.47 | $88,330 | $61,140 | $117,740 | 90 | 0.28 | 1.52 |
| 10 | Maryland profile | $40.98 | $85,240 | $57,190 | $107,890 | 850 | 0.31 | 1.70 |
| 11 | Michigan profile | $39.81 | $82,800 | $54,510 | $92,630 | 490 | 0.11 | 0.61 |
| 12 | Colorado profile | $39.09 | $81,310 | $46,670 | $99,550 | 560 | 0.20 | 1.08 |
| 13 | Massachusetts profile | $38.85 | $80,800 | $64,540 | $100,710 | 530 | 0.15 | 0.80 |
| 14 | Nevada profile | $38.03 | $79,110 | $76,510 | $129,400 | 60 | 0.04 | 0.20 |
| 15 | Montana profile | $37.35 | $77,690 | $50,410 | $108,210 | 110 | 0.22 | 1.22 |
| 16 | Delaware profile | $37.32 | $77,630 | $71,700 | $89,920 | 40 | 0.09 | 0.47 |
| 17 | New Jersey profile | $36.81 | $76,560 | $54,170 | $106,490 | 1,400 | 0.33 | 1.80 |
| 18 | Utah profile | $36.77 | $76,490 | $65,270 | $114,600 | 110 | 0.07 | 0.36 |
| 19 | Minnesota profile | $36.47 | $75,850 | $61,620 | $98,610 | 1,440 | 0.49 | 2.69 |
| 20 | Ohio profile | $36.29 | $75,470 | $59,130 | $87,890 | 760 | 0.14 | 0.75 |
| 21 | Arizona profile | $36.26 | $75,410 | $57,440 | $124,490 | 80 | 0.02 | 0.13 |
| 22 | New Mexico profile | $35.81 | $74,480 | $39,520 | $116,160 | 100 | 0.12 | 0.66 |
| 23 | Pennsylvania profile | $35.05 | $72,900 | $48,140 | $89,000 | 1,730 | 0.29 | 1.57 |
| 24 | South Carolina profile | $34.93 | $72,650 | $53,330 | $89,240 | 170 | 0.07 | 0.40 |
| 25 | Missouri profile | $34.91 | $72,620 | $49,920 | $85,070 | 380 | 0.13 | 0.72 |
| 26 | Tennessee profile | $34.84 | $72,470 | $34,360 | $93,500 | 370 | 0.11 | 0.62 |
| 27 | Georgia profile | $33.96 | $70,640 | $53,290 | $92,310 | 240 | 0.05 | 0.27 |
| 28 | Oklahoma profile | $32.91 | $68,450 | $45,330 | $95,830 | 180 | 0.10 | 0.57 |
| 29 | Vermont profile | $32.89 | $68,400 | $44,620 | $77,870 | 70 | 0.21 | 1.18 |
| 30 | South Dakota profile | $32.74 | $68,090 | $43,310 | $75,770 | 90 | 0.20 | 1.09 |
| 31 | Oregon profile | $32.51 | $67,630 | $47,780 | $100,220 | 330 | 0.17 | 0.92 |
| 32 | Indiana profile | $32.48 | $67,560 | $48,730 | $94,080 | 290 | 0.09 | 0.50 |
| 33 | Iowa profile | $32.43 | $67,450 | $49,760 | $76,380 | 190 | 0.12 | 0.67 |
| 34 | Kentucky profile | $32.10 | $66,770 | $28,890 | $88,900 | 90 | 0.05 | 0.25 |
| 35 | North Dakota profile | $32.10 | $66,760 | $48,270 | $108,460 | 140 | 0.32 | 1.76 |
| 36 | New Hampshire profile | $31.82 | $66,180 | $53,490 | $85,280 | 60 | 0.09 | 0.48 |
| 37 | Florida profile | $31.27 | $65,040 | $46,930 | $83,080 | 170 | 0.02 | 0.10 |
| 38 | Nebraska profile | $31.22 | $64,930 | $46,470 | $86,400 | 290 | 0.28 | 1.56 |
| 39 | Kansas profile | $31.00 | $64,490 | $50,230 | $90,730 | 120 | 0.08 | 0.45 |
| 40 | Idaho profile | $30.99 | $64,460 | $53,950 | $80,870 | 120 | 0.14 | 0.79 |
| 41 | Virginia profile | $30.84 | $64,150 | $36,510 | $94,640 | 350 | 0.09 | 0.47 |
| 42 | Texas profile | $30.68 | $63,810 | $48,250 | $90,190 | 890 | 0.06 | 0.35 |
| 43 | Rhode Island profile | $30.45 | $63,330 | $53,280 | $86,740 | 60 | 0.11 | 0.63 |
| 44 | Maine profile | $30.24 | $62,910 | $49,360 | $78,880 | 290 | 0.45 | 2.46 |
| 45 | Wisconsin profile | $29.41 | $61,170 | $51,040 | $78,120 | 270 | 0.09 | 0.51 |
| 46 | North Carolina profile | $29.26 | $60,860 | $37,050 | $79,450 | 220 | 0.05 | 0.25 |
| 47 | Arkansas profile | $27.89 | $58,000 | $43,800 | $72,320 | 200 | 0.15 | 0.84 |
| 48 | Mississippi profile | $25.79 | $53,640 | $42,440 | $78,390 | 200 | 0.17 | 0.94 |
| 49 | Alabama profile | $25.71 | $53,470 | $38,160 | $78,560 | 220 | 0.10 | 0.57 |
| 50 | West Virginia profile | $25.64 | $53,340 | $49,120 | $56,420 | 40 | 0.05 | 0.28 |
| 51 | Louisiana profile | $22.96 | $47,750 | $39,710 | $87,560 | 290 | 0.15 | 0.82 |
Part of Production Occupations. Compare any area in the wage explorer.
Source and notes
Data: BLS OEWS May 2025, released 2026-05-15. Cross-industry estimates, all ownerships. BLS page: OEWS 51-8021 Stationary Engineers and Boiler Operators.
- Annual wages assume 2,080 hours a year at the hourly rate; occupations BLS publishes on one basis only show an en dash (–) on the other.
- Employment is rounded to the nearest 10 by BLS. Where BLS withholds a cell, nothing is estimated in its place.
- Top industries: nat4d_M2025_dl.xlsx in oesm25in4.zip (BLS OEWS May 2025, national, 4-digit NAICS, cross-ownership). Employment is the industry's rounded total for this occupation; industries whose employment BLS withheld (**) are not ranked.
- Published medians: national_M2021_dl.xlsx to national_M2024_dl.xlsx in oesm21nat.zip to oesm24nat.zip (BLS OEWS May 2021 to May 2024, national, cross-industry, all ownerships) and the May 2025 spine. Each release is shown as published; nothing is computed between them.
Sources
- BLS Standard Occupational Classification 2018, definition of 51-8021, U.S. Bureau of Labor Statistics (public domain).
- O*NET 30.1 Database, 51-8021.00, National Center for O*NET Development, USDOL/ETA (CC BY 4.0).
- OEWS May 2025 national industry-specific estimates, 4-digit NAICS (oesm25in4.zip), US Bureau of Labor Statistics (public domain).
- OEWS May 2021 national estimates (oesm21nat.zip), US Bureau of Labor Statistics (public domain).
- OEWS May 2022 national estimates (oesm22nat.zip), US Bureau of Labor Statistics (public domain).
- OEWS May 2023 national estimates (oesm23nat.zip), US Bureau of Labor Statistics (public domain).
- OEWS May 2024 national estimates (oesm24nat.zip), US Bureau of Labor Statistics (public domain).
- OEWS May 2025 national estimates (oesm25nat.zip), the site's data spine, US Bureau of Labor Statistics (public domain).
Includes information from O*NET 30.1 Database by the U.S. Department of Labor, Employment and Training Administration, used under the CC BY 4.0 license.
Description written 2026-10-17 in our own words from the sources above.