The Kentucky boiler code, set out in KRS Chapter 236 and 815 KAR Chapter 15, requires that most commercial and industrial boilers and pressure vessels in the state be installed by a licensed contractor under a state permit, inspected on a recurring schedule, and operated only while a current certificate of inspection is in force. Running a regulated boiler without that certificate is a Class B misdemeanor, and each day of unlawful operation is a separate offense. The Kentucky Department of Housing, Buildings and Construction (DHBC) administers the program.
What Equipment the Code Covers
The code reaches commercial and industrial boilers and pressure vessels used in manufacturing plants, hospitals, schools, and similar facilities that produce steam or hot water. It applies to new installations, existing equipment, and any modification or repair that affects the structural integrity of the vessel.
Coverage is broader than “steam boiler.” Unfired pressure vessels, water heaters above residential thresholds, and pressure piping connected to regulated equipment are all in scope. New boilers and pressure vessels must be built to the ASME Boiler and Pressure Vessel Code and carry the applicable ASME certification mark. Installation must follow Part 1 of the National Board Inspection Code (NBIC), and repairs and alterations must follow NBIC Part 3. Power boilers and other high-pressure systems draw the closest regulatory attention because a failure can be catastrophic.
Equipment That Is Exempt
KRS 236.060 exempts several categories. If your equipment fits one of these, you avoid the permit and inspection regime, though you keep general liability if something goes wrong and the DHBC can still investigate an accident.
- Residential steam or vapor heating boilers at 15 psi or less, and hot water heating boilers or water heaters at 30 psi or less, in a private residence.
- Any pressure vessel operating at 15 psi or less internal or external pressure.
- Single-wall pressure vessels with an inside diameter, width, height, or cross-section diagonal of six inches or less.
- Pressure vessels with a nominal water capacity of 120 gallons or less used for domestic supply, including air-cushion tanks.
- Portable boilers or pressure vessels on land dedicated to agricultural use and used solely for agricultural purposes.
- Boilers or pressure vessels under federal control, and equipment located at oil refineries.
- Indirectly heated water vessels where heat input stays at or below 200,000 BTU per hour, water temperature stays at or below 210°F, and storage stays at or below 120 gallons.
Antique and hobby boiler-operated tractors and equipment used solely for exhibition get a narrower break: KRS 236.120 and 236.130 exempt them from inspection and certificate fees when the boiler operates at 50 psi or less. That is a fee exemption, not a safety pass. An accident at a show still triggers a full investigation.
Who Can Do the Work
Anyone who installs, erects, or repairs boilers or pressure vessels as a business in Kentucky must first hold a contractor license from the commissioner. Applicants take an examination prepared and administered by the DHBC and pay the examination fee, and the license renews annually, with renewal due no later than the first of the month following expiration. Individual employees working under a licensed contractor do not need their own license.
KRS 236.210 treats unlicensed practice as a code violation carrying the same penalties as other boiler-code offenses. That reaches the customer too, in practical terms: a facility owner who hires an unlicensed contractor shares the compliance risk. Verify a current Kentucky boiler and pressure vessel contractor license before any work starts.
Permits Before Installation or Structural Repair
No one may install, erect, or make repairs affecting the strength of a boiler or pressure vessel without a permit from the DHBC. Permits issue only to contractors licensed under KRS 236.210. Applications typically include engineering plans, manufacturer specifications, and proof of ASME compliance. Each permit covers one interim inspection and one final inspection for issuance of the certificate of inspection; additional inspections requested by the contractor cost extra.
Permit fees scale with the value of the equipment. The schedule in 815 KAR 15:027 starts at $70 for items valued at $2,000 or less and reaches $1,850 for equipment valued at $700,001 and above. Emergency repairs run through a separate track under KRS 236.250, which allows limited exceptions to the permit-first rule when immediate action is needed to prevent a hazard.
Every regulated boiler and pressure vessel needs a pressure-relief device. Where a vessel faces an added hazard from fire or another unexpected external heat source, supplemental relief devices must be sized to keep pressure from rising more than 21 percent above the maximum allowable working pressure. Relief devices must remain accessible for inspection and repair and cannot be arranged so they can be easily disabled.
Inspection Cycles and Certificates
Once a boiler passes its installation inspection and receives a certificate of inspection, it enters a recurring cycle. The interval turns on the equipment type.
- Power boilers: annual inspection, internal where construction permits, with an external inspection under pressure where possible.
- Low-pressure steam, hot water heating, and hot water supply boilers: biennial inspection, internal where construction permits, otherwise external.
Inspections are performed by state boiler inspectors, special boiler inspectors, or owner-user inspectors holding DHBC commissions. They assess construction, condition, safety-appliance function, and compliance with current standards. If a boiler fails, the deficiencies must be corrected before the certificate is renewed. Operating without a valid certificate is illegal, and each day counts as a separate offense.
Reinspection fees are modest next to permit fees. Power boiler internal inspections run from $35 for units with 100 square feet of heating surface or less to $200 for units over 10,000 square feet. External inspections of power boilers run $30 to $35. Biennial reinspections of heating boilers range from $25 for hot water supply boilers and miniature boilers to $55 for boilers with a manway that require internal inspection.
Repairs, Alterations, and Relief Valves
Any repair or alteration to a boiler, pressure vessel, or associated piping must conform to NBIC Part 3. Work that affects the strength of the vessel needs a permit before it starts, and only licensed contractors may perform it. Welded joints on piping have to be documented with the welder’s identification, the weld procedure, and the procedure qualification used.
Pressure-relief valves get an extra layer. Under 815 KAR 15:026, repairs or alterations to relief valves must be done by an organization holding the National Board’s V-R (Valve Repair) stamp, and the valve must be stamped with the V-R mark when the work is complete. This is enforceable, not advisory.
Reporting an Accident
If a boiler or pressure vessel accident or malfunction leaves the equipment inoperative, the owner, user, or insurer must notify the Boiler Inspection Section immediately. Where the accident involves property damage, personal injury, or death, notice goes out immediately by phone or email. No grace period.
After notification, the damaged boiler or its parts cannot be moved or disturbed until a state boiler inspector or special boiler inspector has completed an on-site inspection. The only exception is removing parts to save a human life. Disturbing the scene first can undermine the investigation and lead to additional regulatory consequences.
If the inspector determines the equipment is unsafe for further use, it stays out of service until repaired and re-inspected. An owner who disagrees with the finding can appeal to the commissioner, who orders a joint inspection by the chief boiler inspector and the original inspector before issuing a final decision.
Penalties for Operating Without a Certificate
The DHBC enforces the code through routine inspections, complaint-driven investigations, and post-accident reviews. Under KRS 236.260, inspectors may access premises where regulated boilers are located, and obstructing an inspector is itself a violation.
Under KRS 236.990, operating a boiler or pressure vessel without a valid certificate of inspection, or above the pressure the certificate allows, is a Class B misdemeanor. Each day of unlawful operation is a separate offense, so exposure compounds fast. The same penalty applies to violations of the permit, licensing, and inspection statutes and to anyone who hinders an authorized inspector. Willfully falsifying any statement to obtain, renew, or reinstate a certificate of inspection carries the same penalty under KRS 236.110(5).
For willful violations of KRS Chapter 236 or any related regulation or order, the DHBC can suspend or revoke any license, permit, commission, or certificate the violator holds. The fine attached to a Class B misdemeanor is often the smaller cost. A revoked certificate shuts the boiler down, and for a manufacturing plant or hospital that runs on steam, a few days of downtime typically dwarfs the fine. That is why most compliance failures get resolved quickly once the DHBC issues a citation.