A full HVAC technician in Ontario, someone who can work on both air conditioning or refrigeration systems and gas-fired furnaces, needs two separate credentials from two entirely separate regulators. A Skilled Trades Ontario Certificate of Qualification as a Refrigeration and Air Conditioning Systems Mechanic covers the refrigeration and cooling side. A Gas Technician licence from the Technical Standards and Safety Authority (TSSA) is required separately to legally work on gas-fired equipment. Having one doesn’t cover the other.
The refrigeration and air conditioning side: a compulsory, roughly 9,000-hour trade
Per Skilled Trades Ontario’s information on the Refrigeration and Air Conditioning Systems Mechanic trade, this is a compulsory trade requiring a Certificate of Qualification, earned through an apprenticeship of roughly 9,000 hours, about 8,280 hours of on-the-job work experience and 720 hours of in-school training, split across three 240-hour levels. This certification, known by its code 313A, covers refrigeration and air conditioning systems work.
The gas side: a completely different regulator, not Skilled Trades Ontario
This is the part that surprises a lot of people entering the trade. Working on gas-fired furnaces and appliances isn’t covered by your Skilled Trades Ontario trade certificate at all; it falls under TSSA’s separate Gas Technician certification system. Technicians typically start at the G3 trainee level, which allows tasks like furnace installation or servicing a gas-fired water heater under supervision, then progress to a G2 licence, which allows unsupervised work on any gas-fired appliance under 400,000 BTUs, covering essentially all residential and light commercial equipment. Per TSSA’s contractor registration and certification information, this credentialing runs entirely separately from Skilled Trades Ontario’s apprenticeship and certification system.
Why this matters for your career and business plans
A typical residential HVAC job often involves both an air conditioning or heat pump system and a gas furnace, but your 313A certificate alone only legally authorizes you to work on the refrigeration and cooling side. Without a TSSA gas licence as well, you can’t legally service the gas furnace component of the same system. If you’re planning to eventually run your own HVAC business covering both sides of a typical job, you need to track both credentials for yourself, or make sure your team collectively covers both, rather than assuming one certification covers the full scope of the work.
What to actually do
- Decide whether you’re pursuing refrigeration and air conditioning work, gas work, or both, since the training paths run separately.
- Complete your 313A apprenticeship through Skilled Trades Ontario for the refrigeration and air conditioning side.
- Separately register with TSSA for gas technician training, starting at the G3 trainee level and progressing toward G2 as you gain experience.
- Verify your actual credential status directly with each regulator, Skilled Trades Ontario for your trade certificate and TSSA for your gas licence, rather than assuming one covers the other.