Illinois
For Illinois, governing body is The Illinois Office of the State Fire Marshal; statute citation is Illinois Compiled Statutes, Chapter 430, Subchapter 75, Boiler and Pressure Vessel Safety Act; power boiler inspection interval is annual internal and external inspections while not under pressure, plus an annual external inspection while under pressure; low-pressure boiler inspection interval is biennial inspections; accepted inspector types is division inspectors, commissioned insurance company inspectors, and commissioned owner inspectors, verified against its source on 2026-08-05.
- State
- Illinois
- Governing body
- The Illinois Office of the State Fire Marshal
- Statute citation
- Illinois Compiled Statutes, Chapter 430, Subchapter 75, Boiler and Pressure Vessel Safety Act
- Power boiler inspection interval
- annual internal and external inspections while not under pressure, plus an annual external inspection while under pressure
- Low-pressure boiler inspection interval
- biennial inspections
- Accepted inspector types
- division inspectors, commissioned insurance company inspectors, and commissioned owner inspectors
- Pressure vessel inspection interval
- one triennial certificate inspection (external); internal inspection at the discretion of the inspector where construction permits per nationalboard.org
- Exemptions
- Boilers and pressure vessels under federal control (except those in cities over 500,000 inhabitants); pressure vessels on vehicles under other state authorities; pressure vessels on railroad rights-of-way; pressure vessels for transportation and storage of compressed or liquefied gases per US DOT; boilers and pressure vessels on mine property under Illinois Department of Mines and Minerals; farm agricultural boilers; steam boilers of miniature model locomotives/boats/tractors/stationary engines as a hobby (inside diameter not exceeding 12 inches, grate area not exceeding 1-1/2 square feet); pressure vessels under Illinois Fertilizer Act of 1961; LP gas pressure vessels under Liquefied Petroleum Gas Regulation (except industrial process); steam boilers up to 15 psig/200,000 BTU/hr for heating; hot-water heating boilers up to 30 psig/200,000 BTU/hr; boilers and pressure vessels in private residences or multifamily buildings with fewer than six dwelling units meeting specified category limits; steam boilers of railroad locomotives and traction engines built prior to 1955 in permanent museum collections per nationalboard.org
What the source says
Governing body: The Illinois Office of the State Fire Marshal oversees boiler safety through its Division of Boiler and Pressure Vessel Safety under Illinois Compiled Statutes, Chapter 430, Subchapter 75, Boiler and Pressure Vessel Safety Act. Authorized inspector types: Illinois accepts division inspectors, commissioned insurance company inspectors, and commissioned owner inspectors. Inspection frequency: High-pressure boilers require annual internal and external inspections while not under pressure, plus an annual external inspection while under pressure. Low-pressure boilers require biennial inspections.
— chardonlabs.com, retrieved 2026-08-05
Sources disagree
More than one authority states this, and they do not state the same thing. Both are reproduced with the source each came from — deciding between them is yours, not ours.
Governing body
chardonlabs.com says governing body is The Illinois Office of the State Fire Marshal, as of 2026-08-05.
Governing body: The Illinois Office of the State Fire Marshal oversees boiler safety through its Division of Boiler and Pressure Vessel Safety under Illinois Compiled Statutes, Chapter 430, Subchapter 75, Boiler and Pressure Vessel Safety Act. Authorized inspector types: Illinois accepts division inspectors, commissioned insurance company inspectors, and commissioned owner inspectors. Inspection frequency: High-pressure boilers require annual internal and external inspections while not under pressure, plus an annual external inspection while under pressure. Low-pressure boilers require biennial inspections.
https://www.chardonlabs.com/resources/commercial-boiler-inspection-regulations-by-state/
nationalboard.org says governing body is Office of State Fire Marshal, Division of Boiler and Pressure Vessel Safety, as of 2026-08-05.
Illinois Compiled Statutes, Health and Safety, Chapter 430. Public Safety, Subchapter 75. Boiler and Pressure Vessel Safety Act , Sections 1 through 16. RULES FOR CONSTRUCTION AND STAMPING Construction:
https://www.nationalboard.org/PrintAllSynopsis.aspx?Jurisdiction=Select
Statute citation
chardonlabs.com says statute citation is Illinois Compiled Statutes, Chapter 430, Subchapter 75, Boiler and Pressure Vessel Safety Act, as of 2026-08-05.
Governing body: The Illinois Office of the State Fire Marshal oversees boiler safety through its Division of Boiler and Pressure Vessel Safety under Illinois Compiled Statutes, Chapter 430, Subchapter 75, Boiler and Pressure Vessel Safety Act. Authorized inspector types: Illinois accepts division inspectors, commissioned insurance company inspectors, and commissioned owner inspectors. Inspection frequency: High-pressure boilers require annual internal and external inspections while not under pressure, plus an annual external inspection while under pressure. Low-pressure boilers require biennial inspections.
https://www.chardonlabs.com/resources/commercial-boiler-inspection-regulations-by-state/
nationalboard.org says statute citation is Illinois Compiled Statutes, Health and Safety, Chapter 430. Public Safety, Subchapter 75. Boiler and Pressure Vessel Safety Act , Sections 1 through 16., as of 2026-08-05.
Illinois Compiled Statutes, Health and Safety, Chapter 430. Public Safety, Subchapter 75. Boiler and Pressure Vessel Safety Act , Sections 1 through 16. RULES FOR CONSTRUCTION AND STAMPING Construction:
https://www.nationalboard.org/PrintAllSynopsis.aspx?Jurisdiction=Select
Power boiler inspection interval
chardonlabs.com says power boiler inspection interval is annual internal and external inspections while not under pressure, plus an annual external inspection while under pressure, as of 2026-08-05.
Governing body: The Illinois Office of the State Fire Marshal oversees boiler safety through its Division of Boiler and Pressure Vessel Safety under Illinois Compiled Statutes, Chapter 430, Subchapter 75, Boiler and Pressure Vessel Safety Act. Authorized inspector types: Illinois accepts division inspectors, commissioned insurance company inspectors, and commissioned owner inspectors. Inspection frequency: High-pressure boilers require annual internal and external inspections while not under pressure, plus an annual external inspection while under pressure. Low-pressure boilers require biennial inspections.
https://www.chardonlabs.com/resources/commercial-boiler-inspection-regulations-by-state/
nationalboard.org says power boiler inspection interval is inspected annually both internally & externally while not under pressure; inspected annually externally while under pressure, as of 2026-08-05.
Illinois Compiled Statutes, Health and Safety, Chapter 430. Public Safety, Subchapter 75. Boiler and Pressure Vessel Safety Act , Sections 1 through 16. RULES FOR CONSTRUCTION AND STAMPING Construction:
https://www.nationalboard.org/PrintAllSynopsis.aspx?Jurisdiction=Select
Low-pressure boiler inspection interval
chardonlabs.com says low-pressure boiler inspection interval is biennial inspections, as of 2026-08-05.
Governing body: The Illinois Office of the State Fire Marshal oversees boiler safety through its Division of Boiler and Pressure Vessel Safety under Illinois Compiled Statutes, Chapter 430, Subchapter 75, Boiler and Pressure Vessel Safety Act. Authorized inspector types: Illinois accepts division inspectors, commissioned insurance company inspectors, and commissioned owner inspectors. Inspection frequency: High-pressure boilers require annual internal and external inspections while not under pressure, plus an annual external inspection while under pressure. Low-pressure boilers require biennial inspections.
https://www.chardonlabs.com/resources/commercial-boiler-inspection-regulations-by-state/
nationalboard.org says low-pressure boiler inspection interval is inspected biennially as required by the rules and regulations of the Board, as of 2026-08-05.
Illinois Compiled Statutes, Health and Safety, Chapter 430. Public Safety, Subchapter 75. Boiler and Pressure Vessel Safety Act , Sections 1 through 16. RULES FOR CONSTRUCTION AND STAMPING Construction:
https://www.nationalboard.org/PrintAllSynopsis.aspx?Jurisdiction=Select
Accepted inspector types
chardonlabs.com says accepted inspector types is division inspectors, commissioned insurance company inspectors, and commissioned owner inspectors, as of 2026-08-05.
Governing body: The Illinois Office of the State Fire Marshal oversees boiler safety through its Division of Boiler and Pressure Vessel Safety under Illinois Compiled Statutes, Chapter 430, Subchapter 75, Boiler and Pressure Vessel Safety Act. Authorized inspector types: Illinois accepts division inspectors, commissioned insurance company inspectors, and commissioned owner inspectors. Inspection frequency: High-pressure boilers require annual internal and external inspections while not under pressure, plus an annual external inspection while under pressure. Low-pressure boilers require biennial inspections.
https://www.chardonlabs.com/resources/commercial-boiler-inspection-regulations-by-state/
nationalboard.org says accepted inspector types is Insurance company inspectors commissioned by the division (accepted in lieu of division inspector for insured boilers and pressure vessels; division inspector must do first/initial inspection); owner/user inspectors commissioned by the division (accepted in lieu of division inspector for self-insured boilers and pressure vessels), as of 2026-08-05.
Illinois Compiled Statutes, Health and Safety, Chapter 430. Public Safety, Subchapter 75. Boiler and Pressure Vessel Safety Act , Sections 1 through 16. RULES FOR CONSTRUCTION AND STAMPING Construction:
https://www.nationalboard.org/PrintAllSynopsis.aspx?Jurisdiction=Select
Sources
- chardonlabs.comhttps://www.chardonlabs.com/resources/commercial-boiler-inspection-regulations-by-state/
- nationalboard.orghttps://www.nationalboard.org/PrintAllSynopsis.aspx?Jurisdiction=Select