Definition — what TSSA regulates and who can touch a gas appliance
TSSA enforces Ontario's fuels safety regulations under the Technical Standards and Safety Act. Natural gas and propane appliances fall under TSSA jurisdiction, and only technicians holding the appropriate TSSA gas certification (G1, G2, G3, or a limited-scope ticket, per current TSSA scope definitions) may install, alter, service, or disconnect them.
That includes the gas piping between the meter and the appliance, the appliance itself, and the venting — even if the venting is a plastic sidewall pipe.
When to use this — before you accept a new-furnace install
Walk down to your basement on the day the installer leaves and check the visible signs of a proper TSSA-inspected job. If any are missing, call the installer back — the certificate is what proves the work meets code and what a future home inspector will look for.
- Two PVC pipes running to the outside wall (one intake, one exhaust) with proper clearance from windows, doors, and grade
- A shutoff valve within reach on the gas line, before the flexible connector to the furnace
- A neat gas line — no yellow crush marks, no unions inside the furnace cabinet, dielectric union where required
- A P-trap and proper drain path for the condensate, not just a hose dangling into a bucket
- A visible label / decal from the technician with their TSSA certificate number, or a TSSA sticker
- A CO alarm within 5 metres of every sleeping area (Ontario law)
- A copy of the municipal mechanical permit and (if applicable) the ESA electrical permit
Failure modes — what a bad install looks like
The classic red flags: the old chimney is still visible with an atmospheric water heater still connected to it (a common orphaning issue when the furnace is upgraded but the water heater isn't); a rubber gas hose used as permanent piping (rubber is for portable BBQ-style connections, not permanent); flue vent terminals too close to windows, mechanical intakes, or property lines.
Another common issue in older GTA basements: the combustion-air intake tee-ed off the furnace exhaust rather than run separately to the outside — recirculating flue gases into the burner, which slowly poisons the heat exchanger.
Proof — the paperwork that matters
You should receive three pieces of paper after a furnace install: a completed municipal permit with an inspection sign-off (or a scheduled inspection date), a manufacturer warranty registration confirmation (required to activate the parts warranty on most brands), and a written commissioning report from the installer.
Keep all three in a folder with the furnace's model and serial number. A buyer's inspector will ask for these when you sell the house.
Action — verifying your installer
Ontarians can verify a TSSA certificate by asking the technician for their ticket number and confirming it directly with TSSA. Any legitimate certified tech will be happy to provide it — hiding the number is a red flag.
This is educational content, not legal advice. Confirm current requirements with your local building department, the Technical Standards and Safety Authority (TSSA), and the Electrical Safety Authority (ESA) before starting work.