What are the six work areas and their weights?
The percentages are the share of exam questions in each Major Work Activity. Within each area, the task percentages show how that area's questions are split.
| Code | Major Work Activity | Weight | Tasks (share of the area) |
|---|---|---|---|
| A | Performs common occupational skills Safety and trade practice | 8% | A-1 Maintains safe and healthy workplace (81%) A-2 Maintains continuous learning (13%) A-3 Uses communication and mentoring techniques (6%) |
| B | Performs routine trade activities Tools, piping and refrigerant handling | 16% | B-4 Uses tools and equipment (24%) B-5 Organizes work (21%) B-6 Performs work site preparation (19%) B-7 Performs trade-specific activities (36%) |
| C | Plans installation Planning installs and retrofits | 13% | C-8 Plans installation of standard and high efficiency HVAC/R systems (34%) C-9 Plans installation of control systems (28%) C-10 Plans retrofits (38%) |
| D | Performs installation Installing systems and controls | 21% | D-11 Installs HVAC/R systems (63%) D-12 Installs control systems (37%) |
| E | Performs commissioning Commissioning and start-up | 17% | E-13 Commissions new and retrofitted HVAC/R and control system components (54%) E-14 Verifies system performance (46%) |
| F | Performs maintenance and service Maintenance, service and troubleshooting | 25% | F-15 Maintains HVAC/R systems (30%) F-16 Services HVAC/R systems (43%) F-17 Maintains and services control systems (27%) |
Codes, titles and percentages: Red Seal examination weightings and task matrix, read 2026-09-21. Check the official page before relying on it; the breakdown is revised when the occupational standard changes.
What does that mean for study time?
Maintenance and service (F, 25%), installation (D, 21%) and commissioning (E, 17%) together make up 63% of the exam. Common occupational skills (A) is the smallest area at 8%, but lock-out and safe work (task A-1) makes up 81% of it. A sensible plan puts time where the marks are and then shifts it toward whichever areas a diagnostic shows are weak. The 90-day study plan walks through it.
What else should a 313A candidate know about the trade?
- Skilled Trades Ontario sets the apprenticeship at 9,000 hours: 8,280 on the job and 720 in school.
- 313A is a compulsory trade with a certifying exam. Passing it leads to a Certificate of Qualification, which must be renewed to stay valid.
- The trade is part of the Red Seal program under the title Refrigeration and Air Conditioning Mechanic.
Source: Skilled Trades Ontario trade information, read 2026-09-21.
What does nobody outside the exam body know?
The actual questions. Anyone selling "real" or "recalled" 313A exam questions is either wrong or selling something they should not have. Examen Studio's questions are original, written against the public task list, and labelled with their review status.