Gas-fired packaged boiler assemblies in Canada are required to be safety certified for both residential applications and commercial or industrial facilities. Commercial and industrial packaged gas-fired boilers have been historically evaluated to CSA/CAN1-3.1, “Industrial and Commercial Gas-Fired Package Boilers,” as part of a factory-based safety certification. However, in the first quarter of 2020, notification was provided to the Standards Council of Canada by the proprietary Standards Development Organization (SDO) regarding the withdrawal of CSA/CAN1-3.1. The boiler industry was notified that certification to this document should be concluded by the spring of 2021.


What this means for the industry

Nearly a quarter of the commercial floor space in Canada is heated by packaged boilers, and space heating is by far the biggest energy user in these and other commercial buildings.1 Typically, packaged boiler assemblies are installed in accordance with the markings on the equipment and the installation instructions in conjunction with national and local codes and the certification standard. This information may include, among others, instructions pertaining to clearances, types of adjacent surfaces, and proper vent installation. The withdrawal of this standard has left a void in the Canadian market as boiler manufacturers and third-party certification bodies do not have a valid certification standard for boilers that utilize:

  • Inlet gas pressure greater than 1/2 psi (3.45 kPa);
  • Input rates greater than 12,500,000 Btu/hr.  (3,663,389 W);
  • High-pressure steam greater than 15 psi (103 kPa); and
  • High temperature water greater than 250°F (121°C).

UL proposed options to the Interprovincial Gas Advisory Council.To fill the void left by the withdrawal of the standard, UL made a proposal to the Interprovincial Gas Advisory Council (IGAC) to develop a Canadian Other Recognized Document (ORD) based on UL 795 “Commercial-Industrial Gas Heating Equipment.”

UL prepared a plan and began working with stakeholders, such as the Canadian Boiler Society (CBS) and the applicable Canadian regulatory authorities, to develop the Canadian ORD to ensure safety certification of this equipment would not be interrupted.

When developing new safety Standards, UL typically follows these guidelines to help ensure conformity and clarity:

  • Typically country-specific and factory-based;
  • Harmony with the applicable installation code(s);
  • Intended to reduce the risks of fire, shock, public health, mechanical (casualty) hazards, burglary, or environmental protection;
  • Repeatable test results; and
  • Input from all stakeholders.

Standards include the following content: 

  • Scope;
  • Construction criteria;
  • Both normal and abnormal performance requirements;
  • Markings and instruction manual content; and
  • Production line testing.

Using UL Standard 795 for commercial and industrial boilers currently in place in the U.S. as a guide, UL drafted and submitted a proposed ORD, CAN/UL/ULC-ORD/C795, “Commercial-Industrial Gas-Fired Package Boilers,” to the Standards Council of Canada in January 2021. The scope of the requirements of UL 795 apply to factory-built gas appliances having inputs of more than 400,000 Btu per hour per individual combustion chamber, which require flame failure and other precautions, and are intended primarily for commercial and industrial installation. The appliances covered by the requirements are comfort heating furnaces, heaters, and gas-fired boiler assemblies except watertube boilers having outputs of 10,000 pounds of steam per hour or more. The requirements also apply to all high-pressure steam and high-temperature water gas-fired boiler assemblies regardless of Btu per hour input. Gas-heating equipment covered by the requirements may be operated without a competent attendant being constantly on duty at the burners while the appliances are in operation.

This new Canadian ORD is intended to be similar to the former requirements with added emphasis on the inherent and functional safety of new control technologies utilized in the boiler industry. The standard is anticipated to provide manufacturers of commercial and industrial packaged boiler assemblies a relatively seamless transition to the new requirements. Most boilers currently certified to CSA/CAN1-3.1 and UL 795 will also be in compliance with the newly developed CAN/UL/ULC-ORD/C795. UL anticipates publication of CAN/UL/ULC-ORD/C795 early in the second quarter of 2021. 


What’s next?

Looking to the future and in parallel with the development and publication of CAN/UL/ULC-ORD/C795, UL is leading the development of a new joint Canada-U.S. standard. This binational certification standard will provide an opportunity for a single gas-fired packaged boiler certification to be used for both Canadian and U.S. installations. 

For additional information regarding the development of the standard, visit If you are interested in participating in the standards development process, please visit