TSSA publishes Revision 1 to Ontario's boilers and pressure vessels code adoption document

What happened, and when

The short answer: a small correction to a large 2025 change.

The timeline, from TSSA's own notices:

The 2025 consultation notice stated that section 2 of the document, which adopts CSA B52:23 for mechanical refrigeration, was left unchanged.

What the revision contains

TSSA's March 2026 consultation page listed the proposed revision as three errata, three clarifications and one technical change. The May 2026 publication notice, however, describes Revision 1 as correcting errors that do not involve technical changes.

We report both statements because both are on TSSA's site. We could not tell from the public notices whether the proposed technical change was dropped, reclassified, or simply summarised differently. Neither notice lists the individual items. If a specific clause matters to your work, the revised document itself is the authority, and TSSA's boilers and pressure vessels program is the place to ask.

Why CSA B51:24 matters to boiler companies

CSA B51 is the Canadian boiler, pressure vessel and pressure piping code. Ontario's move to the 2024 edition in August 2025 put it alongside British Columbia, where the 2024 edition took effect on December 31, 2024, and Manitoba, which adopted it from January 1, 2025 with three clauses left voluntary. Alberta took a different route: as our story on Alberta keeping CSA B51:19 explains, a ministerial order there declined to adopt the 2024 edition.

For a company that works in more than one province, or sells across a provincial border, that patchwork is the real news. A single national edition number on a quote or spec sheet may not match what the local regulator enforces.

Analysis: practical steps for owners

This section is our analysis, not TSSA's.

Revision 1 is unlikely to change how a residential boiler crew works on a Tuesday morning. But it is a good trigger for three small jobs:

1. Check your printed material. Proposal templates, warranty sheets and website pages that cite "CSA B51" with an old edition year should be updated or made edition-neutral.
2. Note the date on your site. A boiler company that writes "as of 2026, Ontario enforces CSA B51:24 through TSSA's code adoption document" looks current. One that quotes a 2019 edition looks stale to the commercial buyers who check.
3. Keep a regulator page. A plain page that links TSSA and explains, without giving compliance advice, what the code is and why permits and inspections exist answers buyer questions before they're asked. Our boiler websites service includes one by default.

Reading a code adoption document

For owners who have never opened one, a short guide. A code adoption document doesn't reprint the national code. It names the edition Ontario adopts, then lists Ontario's changes clause by clause: added requirements, deleted clauses and substituted wording. Where the document and the national code conflict, the Ontario document governs.

That structure is why a "minor" revision can still matter. One corrected cross-reference can change which clause applies to a job. When TSSA describes changes as errata and clarifications, it usually means wording was fixed rather than requirements added, but the only way to be sure for your own work is to compare the clauses you rely on.

If that comparison isn't something your team has time for, the honest answer is to ask TSSA, not to assume.

Related coverage

Read our report on Ontario's gaseous fuels amendment FS-279-26, which adds boiler-specific clauses to the gas code, and on TSSA's 2026 inspection certificate fees. Our Ontario page lists the province's regulators and programs.

BoilerNews.ca is a newsroom and marketing service for boiler companies. We don't install, inspect or repair boilers, and nothing here is compliance advice.