Ontario G3 Gas Technician exam preparation
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How the three gas technician certifications fit together, what each one lets you do, and where the G3 exam sits in the path.
| Certification | Roughly what it permits |
|---|---|
| G3 | Entry level. Appliances up to 400,000 BTU/h, working under supervision. |
| G2 | The common working licence. Appliances of any size, with some restrictions. |
| G1 | The most senior, with the broadest scope of work. |
They are sequential: G3 before G2, G2 before G1, with training and logged experience between each. Confirm the current scope and requirements with TSSA — they are the authority and the details change.
Less about hands-on skill than most people expect, and more about codes, gas properties and safety rules. The largest single area is gas properties and combustion; the area that catches people out is the code sections, because those answers cannot be reasoned out.
G3 is the entry-level gas technician certification in Ontario, issued by TSSA. It allows work on gas appliances rated up to 400,000 BTU/h under the supervision of a G2 or G1 holder.
G3 is entry level and works under supervision on smaller appliances. G2 permits work on appliances of any size with some restrictions and is the common working licence. G1 is the most senior, with the broadest scope. Each is earned in turn, with training and logged experience between them.
Complete a TSSA-recognised G3 training course at a college or private trainer, pass the G3 certification exam, and apply to TSSA for your certificate. From there you accumulate supervised experience and further training toward G2.
Yes. The certifications are sequential — G3 first, then G2, then G1, each requiring the one below it along with additional training and experience.