Laws and rules pertaining to boilers, water heaters, and unfired pressure vessels can be found in the following:

The laws and rules are maintained and updated by the State Office of the Code Reviser.

Download our Boilers and Unfired Pressure Vessel Laws Book (updated July 2024).

Rule development

2024 rulemaking

The Board of Boiler Rules and the Washington Department of Labor & Industries (L&I) have adopted an increase in program fees and clarified the definition for pool heaters.

The agency adopted a 6.41% fee increase to cover L&I Boiler Program operating expenses.

The adopted rule amendments take effect July 1, 2025.

Rulemaking documents

Notice of intent (10/22/2024)

Proposed rule language (01/02/2025)

Final adoption (4/22/2025)

All Boiler Program Rulemaking