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Boiler Inspection

Table of Contents

Overview General Requirements
Exemptions Inspections Required
Frequency Fees
Miscellaneous Commonly Asked Questions

The state boiler inspection program implements statutory rules and regulations established to control the design, construction, operation, maintenance and repair of approximately 38,000 boilers and pressure vessels in the state of Colorado. This program was established in the interest of maintaining and assuring safety to the general public, who unknowingly and consistently come in contact with boilers that are located in public and commercial buildings. All schools, nursing homes, restaurants, churches, laundries, hotels\motels, utility companies, refineries and office buildings contain boiler and\or pressure vessels. Boilers and pressure vessels have the force of a bomb and can result in a catastrophic explosion, causing property damage, personal injury or even death.

General requirements of this program include:

  • Rules for construction and stamping; Boilers and pressure vessels - ‘95 edition of ASME Code, Sections I, II, IV, VIII (1) & (2), X, B31.1 and CSD-1.
  • For welded repairs and alterations; ‘95 edition of the National Board Inspection Code (NBIC)
  • For chemical and petroleum industries only; API 510 and 570 is acceptable for inspection and repairs in lieu of the NBIC.

Exemptions to the State Boiler Program:

  1. Boilers\pressure vessels owned or operated by the federal government.
  2. Locomotive boilers subject to the Federal Locomotive Inspection Act.
  3. Boilers\pressure vessels installed in private residences.
  4. Service and domestic water heaters where none of the following is exceeded;
    • A heat input of 200,000 btu’s per hour
    • 120 gallons capacity
    • 210o F water temperature

Inspections required:

All boilers regardless of BTU input if installed as a closed system. Domestic hot water heaters exceeding 200,000 btu’s per hour or greater than 120 gallons or may exceed 210o F water temperature. All other pressure vessels are inspected upon a letter of request.


All boilers’ domestic water heaters are inspected annually with a certificate of operation issued.


Each boiler, pressure vessel or hot water heater inspected is presently subject to a $22.00 fee. ASME and National Board Joint Reviews are performed by the state and fee of $200.000 per day is charged for this service plus travel and expenses.


Insurance inspectors holding a valid NB commission will be issued a state commission upon completion of an interview with the state chief boiler inspector.

Any welded repairs to boilers and\or pressure vessels must be performed by a National Board certified "R" stamp holder.

All boilers installed in Colorado must be National Board Registered. Pressure vessels at this time are highly recommended to be registered with the National Board and should be a mandatory requirement in the near future.

Commonly asked questions:

Q: Why haven’t I received my boiler operating certificate?

A: In order to receive an operating certificate, the fee must be paid in full and any requirements noted during the inspection must be brought into compliance by the owner.

Q: What are my duties as an owner, installer, contractor when installing a new boiler?

A: One of the three should notify the boiler inspection division of the location, and request an inspection prior to placing the boiler in service. The ultimate responsibility for this action is the owner of the boiler.

Q: Why does an insurance inspector inspect my boiler?

A: If you maintain insurance on your boiler, the insurance inspector who is commissioned by this state will perform the required annual inspection after the initial installation inspection which is required to be performed by a state inspector. If the insurance is canceled, a state inspector will inspect your boiler.

Q: How can I get a duplicate billing statement or operating certificate?

A: Any duplicate statement or certificate can be generated from our office and sent to you at any time.

Q: What are procedures regarding welded repairs and construction requirements of boilers and\or pressure vessels?

A: This technical question can be answered by the chief boiler inspector who has the expertise and background of welding and construction.

Q: What are the licensing requirements for boiler operators?

A: The state of Colorado does not require licensing of boiler operators; however, the city and county of Denver does mandate operator licensing requirements.

Q: What is the procedure if I cannot complete repairs to my boiler within the 45 days allotted to bring it into compliance?

A: Contact the chief boiler inspector who will consider the seriousness of the requirement relative to safety. A request for an extension of time to complete repairs will be granted by the chief boiler inspector.

For any information regarding boilers and pressure vessels you may contact: Boiler Inspection Division, 1515 Arapahoe St, Twr 2, Ste 750, Denver, Co 80202 Tele: 303-572-2900 or 2903 FAX: 303-620-4993

All Applicable Rights Reserved, Copyright 2004 Colorado Department of Labor and Employment