Fast facts
| Certificate | Domestic Appliance Technician (DA), commonly searched as gas appliance technician licence |
|---|---|
| Fuel family | Natural gas and propane (vapour) |
| Issued by | Technical Standards and Safety Authority (TSSA) |
| Legal basis | O. Reg. 215/01 (Fuel Industry Certificates), s. 3 (1); scope in s. 31 |
| Exam pass mark | 75% (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) |
| Renewal | Every 2 years; $50 late payment fee after the renewal date |
| Transferable | No (O. Reg. 215/01, s. 17) |
Last verified August 19, 2026 against the sources listed below.
What can a DA holder legally do in Ontario?
A DA holder may install, alter, purge, activate, repair, service or remove any unvented residential natural gas or propane appliance, or a vented refrigerator, with an input of 100,000 Btuh or less, other than a construction heater. In doing that work, the holder may:
- Work on piping, tubing and components to those appliances downstream of the meter or propane vapour service valve
- Maintain, service or replace mechanical or electrical components, moisture ducts and accessories essential to the appliance's operation
- Service and replace electrical switches, fuses, components and control wiring directly related to the appliance
Boundaries of the DA
- Electrical work beyond the appliance itself requires an electrician certificate of qualification (O. Reg. 215/01, s. 31 (3))
- Construction heaters are excluded; they have their own CH-class certificates
The full scope wording is in O. Reg. 215/01, s. 31, 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 DA in Ontario?
Prerequisite
You must already hold a G.3 certificate, or a valid certificate of qualification as an operating engineer under O. Reg. 219/01, when you apply (O. Reg. 215/01, s. 7). See the G3 Gas Technician 3 certificate requirements.
The training route
- 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.
- 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.
- 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)).
- 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 DA 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 DA sits in the ladder
A DA holder can act as the supervising certificate holder for a G.3 within the DA scope.
Related certificates and trades
Official verification sources
- RegulationO. Reg. 215/01, Fuel Industry Certificates (e-Laws)
- Certifying bodyTSSA: Fuels Industry Professional certification
- FeesTSSA Natural Gas & Hydrogen Fee Schedule
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.