Gas work is regulated separately from plumbing and heating everywhere in Canada, and it is compulsory: you cannot legally connect or alter a gas system without the right gas technician or gasfitter certificate. In Ontario the certificates are issued under the Technical Standards and Safety Authority (TSSA) in three classes, G3, G2 and G1, and the difference between them is the size of the system you are allowed to work on, measured in BTUH (British thermal units per hour). Getting the class structure right is the whole game in this trade, because working above your class is illegal.
The TSSA class structure (get this right)
In Ontario, the three Gas Technician classes are defined by capacity, not by task:
- G3 is the entry class. A G3 may work on residential and small commercial systems up to 400,000 BTUH, but only under the supervision of a G2 or G1. G3 is the starting ticket on the way to G2; it is not an "appliance connections only" licence.
- G2 is the workhorse ticket. A G2 may work unsupervised on residential and light-commercial systems up to the same 400,000 BTUH ceiling: boilers, furnaces, water heaters and fireplaces. Most HVAC technicians hold a G2 alongside their refrigeration ticket.
- G1 is the full-scope tier. A G1 may work on systems over 400,000 BTUH, including large commercial and industrial installations and high-pressure piping.
So G2 and G3 share the up-to-400,000 BTUH ceiling; the practical difference between them is that a G3 must be supervised and a G2 works on their own. G1 is the step up to the bigger systems above that ceiling.
It is compulsory, and it varies by province
Gas certification is compulsory across Canada, but the body and the class labels change by province. In BC, Technical Safety BC issues Gas Fitter certificates: Class B covers systems up to 120 kW (residential), and Class A is the full commercial and industrial scope. Alberta issues a Gas Fitter certificate through its apprenticeship system. Nova Scotia is strict: you must hold a Nova Scotia gas fitter licence to work there even if you are certified in another province. Gas fitter certification is compulsory in Nova Scotia, Quebec, Alberta, British Columbia, Yukon, the Northwest Territories and Nunavut, and is mandatory in Ontario through the TSSA system. Class labels and supervision rules vary by province, so confirm with your provincial gas authority.
Who can pull a gas permit
All gas work is done under permit and inspected by the Authority Having Jurisdiction (the AHJ), which is the TSSA in Ontario or Technical Safety BC in BC. In practice the permit is tied to a certified gas technician or a licensed gas contractor: you cannot legally pull a gas permit, or sign off the work, without holding the appropriate class for the system. A G3 working under supervision does so on a G2's or G1's authority, not their own.
Quebec is its own system
In Quebec, gas work runs through the CCQ competency card and the Regie du batiment du Quebec (RBQ), with gas and plumbing contractors regulated through the CMMTQ (Corporation des maitres mecaniciens en tuyauterie du Quebec). A certificate earned elsewhere does not by itself let you do gas work in Quebec.
Code, kit and costs (estimates)
You work to CSA B149.1, the national Natural Gas and Propane Installation Code. The kit is modest, and the G2 training program is the main up-front cost. Approximate ranges, so confirm current prices:
- The G2 training program: roughly $3,000 to $10,000, with exam fees on top of around $150 to $300.
- Gas detection equipment: roughly $500 to $2,000.
- A combustion analyzer: roughly $800 to $2,500.
- Gas-rated CGL insurance: roughly $3,500 to $7,000 a year.
Adding gas certification on top of a plumbing or HVAC ticket is often an incremental $5,000 to $15,000 in year one.
What you can charge (estimates)
Gas callouts bill at a premium over plumbing, and rates vary by region, so treat these as indicative ranges, not fixed prices:
- A gas line install: roughly $300 to $800 per line.
- An annual furnace safety check: roughly $150 to $300.
- A gas appliance install: roughly $200 to $600, labour only.
Confirm your own numbers against the local market before you quote.
Common mistakes
- Treating G3 as "appliance connections only". A G3 covers up to 400,000 BTUH, the same ceiling as a G2, but must work under supervision. The real difference is supervision, not scope.
- Working above your class. A G2 cannot legally take on the over-400,000 BTUH systems that need a G1.
- Assuming a plumbing or HVAC ticket covers gas. Gas is a separate compulsory certification.
- Crossing a provincial line on the old ticket. Nova Scotia, for one, requires its own licence regardless of where you certified.
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