OCOntario Certification Registry

Fuel Industry Certificate Record

Gas Technician 3 (G.3) Certificate

The G.3 is Ontario's entry-level gas certificate. It lets you work on natural gas and propane systems under the supervision of a G.1, G.2 or DA certificate holder, and it is the prerequisite for the G.2.

Fast facts

CertificateGas Technician 3 (G.3), commonly searched as G3 gas licence, gas technician 3 or G3 course
Fuel familyNatural gas and propane (vapour)
Issued byTechnical Standards and Safety Authority (TSSA)
Legal basisO. Reg. 215/01 (Fuel Industry Certificates), s. 3 (1); scope in s. 22
Exam pass mark75% (TSSA Gas/Oil Burner Technician certification policy, updated March 2025)
Exam fee$89 per attempt; $255.50 to challenge without training (from May 1, 2026, plus HST)
Certificate fee$136 initial and renewal (from May 1, 2026, plus HST)
RenewalEvery 2 years; $50 late payment fee after the renewal date
TransferableNo (O. Reg. 215/01, s. 17)

Last verified August 19, 2026 against the sources listed below.

What can a G3 holder legally do in Ontario?

Under the general supervision of a G.1, G.2 or DA certificate holder, and only for work the supervising holder has documented and signed off, a G.3 holder may:

  • Install, test, activate or purge gas piping or tubing under two and a half inches in diameter, downstream of the natural gas meter or propane service valve up to the appliance control valve, including completing the pressure test tag
  • Reactivate a previously installed or converted appliance
  • Clean and lubricate an appliance
  • Clean, remove or replace a vent connector, venting or a draft control device

Boundaries of the G3

  • A G.3 holder must not perform the initial activation of a new or newly converted appliance (O. Reg. 215/01, s. 22 (2))
  • Under the direct supervision of a G.1, G.2 or DA holder, a G.3 holder may carry out any function within the supervising holder's scope (s. 22 (4))

The full scope wording is in O. Reg. 215/01, s. 22, which prevails over any summary.

Is a certificate legally required for gas work?

Under O. Reg. 212/01 (Gaseous Fuels), s. 6 (1), no person may install, alter, purge, activate, repair, service or remove any appliance or equipment used in the handling or use of gas unless they hold a certificate for that purpose. The only exception is working in the physical presence of someone who holds the appropriate certificate.

The requirement is in O. Reg. 212/01, s. 6 (1). Working without the certificate is an offence under the Technical Standards and Safety Act, 2000.

How do you get the G3 in Ontario?

Prerequisite

None beyond the approved training program and exam. The G.3 is the entry certificate into gas work in Ontario.

The training route

  1. Complete an approved program at an accredited training provider. Certification requires a TSSA-approved curriculum delivered by an accredited provider (O. Reg. 215/01, s. 5 (1)), with a 75% pass on each module and on the practical evaluations.
  2. Apply for the TSSA certification exam. Your provider submits proof of training; you book through the TSSA Client Portal. The practical assessment stays valid for 12 months after the program.
  3. Pass the TSSA certification exam with 75% or higher. Each attempt, including rewrites, is billed as a separate exam. Failing three times means completing a full accredited program before another attempt (O. Reg. 215/01, s. 5 (4)).
  4. Pay the certificate fee. $136 for the initial certificate (from May 1, 2026, plus HST), per the TSSA Natural Gas & Hydrogen Fee Schedule.

The challenge route

Experienced workers can challenge the exam without formal training if TSSA is satisfied they hold equivalent knowledge and competence (O. Reg. 215/01, s. 5 (5)). The challenge examination costs $255.50, requires documented proof of work experience where the certificate has prerequisites, and still ends in a practical skills assessment.

How often does the G3 need to be renewed?

Every two years. TSSA's fee schedules list the certificate fee as biennial, and the renewal costs $136 (from May 1, 2026, plus HST) with a $50 late payment fee after the renewal date. For the gas and oil burner classes, TSSA's certification policy anchors the expiry to the second anniversary of the holder's birthday after issue.

Working on an expired certificate is prohibited outright: O. Reg. 215/01, s. 4 (1) says a person who fails to renew shall not do any work under the certificate after expiry. You can still renew up to one year after expiry, completing any upgrading course the director specifies. After one year, the certificate is gone and you start over as a new applicant (s. 4 (5)).

Where the G3 sits in the ladder

Holding the G.3 is the legal prerequisite for applying for the G.2 (O. Reg. 215/01, s. 7). Next step: G2 Gas Technician 2 certificate requirements.

Related certificates and trades

Official verification sources

How this record is built: scope, prerequisites and renewal law are read directly from O. Reg. 215/01 as consolidated on e-Laws; fees come from TSSA's published fee schedules and the pass mark from TSSA's certification policies. The page is assembled programmatically from those verified facts and reviewed before publishing. Facts not verified against a primary source are marked as not published rather than estimated.