Canada · Trade examWhat's on the Red Seal plumbing exam?
Drainage work leads the seven areas:
| Major work activity | Questions |
|---|---|
| Sewers, sewage treatment systems and DWV systems | 32 |
| Water service and distribution | 24 |
| Fixtures, appliances and water treatment systems | 17 |
| Low-pressure steam and hydronic systems | 16 |
| Common occupational skills | 14 |
| Tube, tubing and pipe | 13 |
| Specialized systems | 9 |
Most of the exam is about doing the work: 60 to 70% of questions are procedural and application, 15 to 25% knowledge and recall, and 10 to 20% critical thinking.
The formula and reference sheet
It's on the exam information page, and the same sheet is handed out at the exam. It covers:
- Measurement units and constants
- Coefficients of linear expansion
- Conversion factors
- General formulas such as Boyle's, Charles' and Watt's laws
- Hydronic thermal formulas
- Area, perimeter and volume
An acronym list comes with it. Red Seal's exam guide adds that where a trade uses a code book, the exam refers to the national code book, and questions won't always say they're about code.
Plumber in Ontario
Plumber is one of Ontario's compulsory trades, so working in it there needs a Certificate of Qualification, a provisional one or a registered training agreement.
Getting your plumbing Red Seal
Apprentices write the exam at the end of their training, and experienced plumbers can apply to challenge it. Your province or territory sets the hours, fees and booking.
Sources: Red Seal · Skilled Trades Ontario and 2 more. Checked October 2026.
- Red Seal: Plumber ↗
- Red Seal: Plumber exam information ↗
- Red Seal: Exam Preparation Guide ↗
- Skilled Trades Ontario: Work in the compulsory trades ↗
Rules and fees can change, so check the official site before your test.
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