Gas Safety and Planning
Ontario Gas Fitter Qualifications: G1, G2 and Contractor Registration
Before hiring for gas work in Ontario, check both the contractor business and the technician. They have different registration and qualification requirements.
Before you compare
Start with the property and equipment
In Ontario, G1 and G2 are individual certificate categories with different scopes, while a fuels-contractor business must be registered with TSSA to contract for regulated work. A G2 generally works on approved gaseous-fuel appliances and equipment up to the certificate's rated-input limit; a G1 has a broader input scope and prerequisite experience. The homeowner should verify the current contractor record and ask how the attending technician's certificate covers the exact project.
Check the business and the technician separately
A fuels contractor is the business that offers and contracts for regulated work. TSSA maintains a public contractor directory. A gas technician is an individual holding a certificate category that authorizes specified work, subject to conditions and scope. A technician certificate does not automatically register an unrelated business.
When reviewing a quote, match the business name to the directory and ask who will perform the work. The invoice and warranty path should use the same accountable business identity. This two-layer check is more precise than asking only whether someone is "licensed."
- Verify the contractor business in the TSSA directory.
- Ask which certified individual will attend.
- Match the certificate scope to the project.
- Keep the quote and invoice under the verified entity.
What G2 commonly means
The G2 certificate covers work on specified gaseous-fuel appliances and equipment within the rated-input scope set by Ontario rules and training requirements. It is widely relevant to residential fireplaces, pool heaters, ranges and gas lines when the appliance and system fall within that scope. Exact authorization still depends on the task and conditions.
A homeowner should not total inputs and independently decide that a certificate applies. Ask the contractor how the project is assigned and supervised. Multi-appliance systems, larger equipment or unusual work may require different qualifications or oversight.
What G1 adds
G1 is a higher certificate category with broader rated-input scope and experience prerequisites. It is relevant to larger equipment and work beyond the G2 limit, but "higher" does not make every G1 the right contractor for every residential project. Current registration, experience with the equipment and a clear quote still matter.
For a typical homeowner quote, the useful question is not whether the company can advertise its highest credential. It is whether the business and assigned technician are authorized and experienced for the specific fireplace, gas line, pool heater or appliance work being proposed.
- Broader input scope does not replace contractor registration.
- Certificate category is one part of project fit.
- Current status and conditions matter.
- Relevant equipment experience remains valuable.
Before you choose equipment
Find the right fit for your home
Tell us which models you like and where you want the appliance. We can help check the fuel supply, venting, space and access before you buy.
Why supervision and task boundaries matter
Projects can include apprentices, helpers and several trades. The registered contractor is responsible for assigning regulated work within qualification and supervision requirements. Electrical work, digging, masonry, pool plumbing and structural work may need other qualified contractors.
Ask who will do each part of the job. A gas certificate does not cover every part of a renovation. Your quote should explain who plans and installs the gas line, handles electrical work, creates openings and finishes, and checks the appliance at startup. Knowing who does what helps avoid delays and unsafe shortcuts.
Verify current records instead of marketing language
Use TSSA's official contractor search and official certification information. Search the legal and operating names, compare location details and note the date. If a listing cannot be reconciled with the quote, contact TSSA. Do not rely on a copied badge, old certificate photograph or a directory hosted by an unrelated lead-generation site.
Ask the contractor to explain terminology accurately. Look for a company that explains its registration, the technician's qualifications and exactly what the job includes. Treat registration details as current only after checking TSSA's official records.
- Official TSSA directory.
- Exact business identity and location.
- Current date of verification.
- Direct clarification for any mismatch.
Make sure the qualifications match your job
A clear quote names the fuel and appliance, explains the line route and any assumptions about the existing system, and lists the gas work, equipment, testing and startup checks. It should also explain who handles any required permits or inspections, work by other contractors and anything not included. Qualifications matter, but the quote still needs to explain the job.
Keep the quote, approved changes, final invoice, manuals and any records provided when the job is finished. For service, keep the model, serial and findings. The hiring decision should account for both authorization and who remains accountable for the work, without asking the homeowner to become the technical authority.
Look beyond the certificate name
Certificate category answers a regulatory scope question; it does not rank customer service, fireplace design ability or pool-system knowledge. Compare relevant project experience, current manufacturer documentation, written communication and the plan for related trades alongside authorization. A higher certificate category does not replace a clear quote for your home.
Conversely, years of informal experience do not replace required registration and certification. The strongest hiring evidence is the combination: current official records, a technician assignment that fits the work, transparent assumptions and a documented completion process. That gives the homeowner a fair basis for comparing bids without making technical judgments outside their role.
Questions we hear
Frequently asked questions
No. The required certificate depends on equipment input, task and scope. G2 commonly covers many residential appliances within its limits, while larger or different work can require G1 or other qualifications.
No. Registration applies to the fuels-contractor business. G2 is an individual technician certificate category. Verify the business and the people assigned to regulated work.
Individual certification does not replace the business registration required to contract for regulated fuels work. Confirm the accountable contractor in TSSA's current directory.
Start with TSSA's official contractor and certification resources. Contact TSSA directly when names, scope or current status are unclear.
References
Sources and further reading
Ask about your project
Tell us about the property and equipment
Send the service address, timing, appliance model and safe photos that show the work area.