How often boilers must be inspected, what the inspection covers, who is allowed to perform it, and how the rules change from state to state. A plain-English reference for building owners and managers.
A boiler inspection is a jurisdictional safety examination of a boiler or pressure vessel, required so the equipment can legally operate. Almost every state builds its program on two national standards: the ASME Boiler and Pressure Vessel Code, which governs how the equipment is built, and the National Board Inspection Code (NBIC), which governs how it is inspected in service. Because of that shared foundation, the mechanics of a boiler inspection look broadly similar across the country, even though the deadlines, fees, and filing details are set state by state.
The output of a passing inspection is a Certificate of Inspection (sometimes called a Certificate of Operation). The certificate has an expiration date, must usually be posted at or near the equipment, and a boiler may not legally operate without a current one. If you need the service itself rather than the rules, see our boiler inspection and pressure vessel testing page.
Inspection frequency depends mostly on the type of boiler. While the exact intervals are set by each jurisdiction, the most common pattern across National Board states is:
Some jurisdictions require both an internal inspection (with the boiler shut down and opened) and a separate external/operating inspection while the boiler is running. The interval can also shorten if the boiler is in poor condition or has a history of violations.
There is no single national boiler inspection deadline. Each state, and in some cases each city, sets its own registration, frequency, filing window, and fees, and a minority of states have limited or no statewide boiler law. The table below shows the general pattern alongside two jurisdictions Insparisk works in heavily. Always confirm the rule for your exact location before relying on it.
| Jurisdiction | Authority | Typical frequency | Notes |
|---|---|---|---|
| National Board pattern (most states) |
State boiler/pressure-vessel program | High-pressure: annual Low-pressure: biennial |
Certificate of Inspection required to operate; intervals follow the NBIC. |
| New York City | NYC Department of Buildings | Annual (low-pressure) | Inspection report must be filed within 14 calendar days of the inspection; cycle runs Jan 1–Dec 31. See our NYC boiler inspections page. |
| Maryland | Maryland Dept of Labor, Board of Boiler Rules | High-pressure: annual Low-pressure: biennial |
Inspection by a commissioned Authorized Inspection Agency; valid Certificate of Inspection required. See our Maryland boiler inspections page. |
| States with limited/no statewide law | Insurer's jurisdictional inspector | Set by insurer | Where a state has no boiler law, your property insurer's National Board commissioned inspector usually drives the inspection cycle. |
Not sure what applies to your building? Use our free compliance assistant to research the boiler and building requirements for your city and state.
Check Requirements for Your Address →A jurisdictional boiler inspection is more than a visual once-over. A typical examination includes:
Boiler inspections must be performed by an inspector holding a National Board Commission, working either for the state (a state boiler inspector) or for an Authorized Inspection Agency, often tied to a property insurer. Building owners generally arrange the inspection through their jurisdiction or through a commissioned agency. Insparisk performs and coordinates jurisdictional boiler inspections through commissioned inspectors and files the certificate on your behalf.
Operating a boiler on an expired or missing Certificate of Inspection is a violation in most jurisdictions. Consequences range from monetary penalties and late fees to an order to take the boiler out of service, and an expired certificate can create an insurance coverage gap. Because deadlines are tied to the certificate anniversary rather than a single statewide date, the practical risk is simply losing track. Tracking each certificate's expiration is the single most effective way to stay compliant.
In most states, high-pressure (power) boilers are inspected annually and low-pressure heating boilers every two years. The exact interval is set by your state or city, and shorter intervals can apply to equipment in poor condition.
In the large majority of states, yes. A boiler generally cannot legally operate without a current Certificate of Inspection. A minority of states have limited or no statewide boiler law, and in those areas the inspection is usually driven by the property insurer's jurisdictional inspector.
It is the document issued after a passing inspection that authorizes the boiler to operate. It carries an expiration date, usually must be posted at or near the equipment, and must be renewed each inspection cycle.
An inspector holding a National Board Commission, working for the state or for an Authorized Inspection Agency. Insparisk performs and coordinates these jurisdictional inspections and handles the filing.
Yes. Low-pressure heating boilers are covered in most jurisdictions, typically on a two-year cycle. The interval is longer than for high-pressure boilers, but the requirement still applies.
Insparisk handles boiler and pressure vessel inspections, certificate filing, and deadline tracking nationwide.
See Boiler Inspection Services