Gas work carries the highest regulatory intensity of any trade in Canada because of the fire and explosion risk, so every province controls who may do it and how. The pattern mirrors electrical: an individual needs a gas certificate (a gasfitter class or, in Ontario, a TSSA gas technician certificate), and a business that does gas work for hire usually needs a separate contractor registration that pulls the permits. Gas fitting is a separate trade from plumbing in most provinces, so a plumbing ticket does not carry gas rights. If you do HVAC or refrigeration, you will often need certification in both the mechanical trade and the gas work.
Ontario: the TSSA G1, G2 and G3 classes
In Ontario, gas work is regulated by the Technical Standards and Safety Authority (TSSA). A gas technician holds one of three certificates, and the boundary between them is set by appliance size in BTUH (British thermal units per hour) of input, not simply by appliance type:
- G3: the entry-level certificate. A G3 can work on systems up to 400,000 BTUH, but only under supervision. It is reached through an approved training course and a TSSA exam. It is a starting class, not an "appliance connections only" ticket.
- G2: covers the same up-to-400,000 BTUH ceiling as G3, but allows the holder to work without that supervision. It is earned with G3 experience plus further training and a TSSA exam.
- G1: the top class, covering all gas work, including the large commercial and industrial systems over 400,000 BTUH. It requires a valid G2 plus substantial field experience (including supervised hours on the larger systems) and an exam.
Note that G2 and G3 share the up-to-400,000 BTUH limit; the practical difference between them is supervision, not appliance size. G1 is the tier that adds the over-400,000 BTUH work.
Contractor side: a company doing gas work for hire in Ontario must hold a TSSA Registered Fuels Contractor registration. Only registered fuels contractors are legally allowed to do gas work for hire; the individual technician still needs their own G1, G2 or G3.
British Columbia: two gasfitter classes plus a contractor licence
BC certifies individual gasfitters in two classes through SkilledTradesBC, both compulsory since December 2023:
- Gasfitter Class A: all gas work, including high-pressure commercial and industrial systems.
- Gasfitter Class B: lower-pressure work, the residential scope. Class B became a Red Seal trade in BC effective 1 January 2025 (see Red Seal Explained).
On top of the personal certificate, the business must be a licensed gas contractor with Technical Safety BC, and that licensed contractor obtains the installation permit before installing regulated gas equipment. Workers file compliance declarations electronically after the job.
Who pulls the gas permit by province
This is where moving around catches people out, because the permit authority is not always who you would expect:
- Ontario: the Registered Fuels Contractor pulls the permit via the TSSA.
- British Columbia: the licensed gas contractor pulls the installation permit via Technical Safety BC.
- Alberta: gasfitter Class A and B are compulsory trades; permits run through the Safety Codes Act system and accredited municipalities.
- Manitoba: gas installation permits are issued by the Office of the Fire Commissioner. This is not Manitoba Hydro (which does electrical permits) and not the apprenticeship body. It is a common and costly mix-up.
- Quebec: gas work falls under the RBQ specialised-contractor licence, and workers on covered sites need a CCQ competency card.
- Other provinces and territories: the provincial apprenticeship body certifies the gasfitter, and a provincial safety authority issues permits; confirm locally.
HVAC and refrigeration, and the gas overlap
Refrigeration and air conditioning mechanic is a compulsory trade in most provinces, and a Red Seal trade. Many HVAC and refrigeration jobs also involve gas-fired equipment, which means you may need both the refrigeration certificate and a gas certificate. In Quebec the picture is more layered still: a refrigeration worker may need a provincial qualification certificate (issued by the MESS through the CAQP) plus a CCQ competency card for construction sites, with around 8,000 documented hours and a French-language exam. Whether out-of-province refrigeration certificates are recognised exam-free under the CFTA is not reliably published, so confirm directly with the CAQP before assuming.
A real blind spot: the gasfitter Red Seal
Even though gas fitting is a Red Seal trade in some provinces, a gasfitter Red Seal endorsement is not recognised in Ontario or Saskatchewan. A tradesperson who earned gas tickets in a Red Seal province can be caught out assuming the endorsement carries everywhere. It does not, for gas. Always check the destination province's specific recognition rules (see Interprovincial Mobility and the CFTA).
Common mistakes
- Assuming a plumbing ticket includes gas. Gas fitting is a separate trade in most provinces.
- Reading G3 as "appliance connections only". G2 and G3 share the up-to-400,000 BTUH ceiling; G3 simply needs supervision.
- Thinking Manitoba Hydro issues gas permits. Manitoba gas permits come from the Office of the Fire Commissioner.
- Expecting a gasfitter Red Seal to be recognised everywhere. It is not recognised in Ontario or Saskatchewan.
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