Ontario G3 Gas Technician exam preparation
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The Ontario G3 exam pass mark is commonly cited as 75% — 124 of 165 questions — sat over 3 hours 30 minutes in a single session.
75%. On a 165-question paper that means 124 correct answers, with 41 marks to spare. It is a percentage of the whole paper rather than a threshold per topic, so a weak area can be carried by strength elsewhere — but only up to a point, because the largest topics contribute enough questions to sink a paper on their own.
Requirements change. Confirm the current pass mark with TSSA or your training provider rather than taking any study site's word for it, this one included.
Hard in a specific way: broad rather than deep. Very little of it asks you to reason through a problem you have not seen. Most of it asks whether you know a figure — a clearance, a pressure, a flammability limit, a test duration — and those either are in your head on the day or they are not.
That is why the exam separates people by how they studied rather than by aptitude. Reading a manual front to back feels productive and leaves very little behind. Answering questions, getting them wrong, and finding out why is slower per hour and far more durable.
3 hours 30 minutes across 165 questions works out to about 76 seconds each. That is comfortable for recall questions and tight for the pipe sizing and combustion air ones, which is the case for pacing practice: sit at least one full timed paper before the real one so the clock is not a new experience on the day.
Aim for 80%, not 75%. Practice conditions flatter you — familiar wording, no nerves, no three-and-a-half-hour fatigue — and the gap between a practice score and an exam score is real. Five points of buffer is the cheapest insurance available.
Almost always the code sections. CSA B149.1 questions are specific and unreasonable to derive: the answer is a number in a table. Candidates who are comfortable on appliances and combustion theory routinely arrive at the code questions with nothing to fall back on. Drill them first, not last.
The G3 exam pass mark is commonly cited as 75%. On a 165-question paper that is 124 correct answers, leaving room to lose 41. Confirm the current requirement with TSSA or your training provider before you sit it.
It is not conceptually difficult, but it is broad and specific. Most of what decides a pass is recall of code figures and gas properties rather than reasoning, which means the exam rewards drilling and punishes skim-reading.
3 hours 30 minutes for 165 questions, sat in one session without pausing. That is roughly 76 seconds per question.
Aim for 80% in practice rather than 75%. The buffer covers exam-day nerves and question wording you have not seen before, both of which reliably cost a few marks.
The code sections. Gas Properties & Combustion, Gas Code & Piping, Electricity & Controls, Appliances & Heat Transfer, Safety & Workplace, Venting & Combustion, Regulations & TSSA, Controls & Ignition, Tools & Measurements are all examinable, and the CSA B149.1 questions are the ones that cannot be reasoned out from first principles — either the figure is memorised or the mark is gone.