The Last Mile to Your 313A Refrigeration and Air Conditioning Systems Mechanic Certificate of Qualification

Who This Guide Is For

You're an apprentice in Ontario's 313A — Refrigeration and Air Conditioning Systems Mechanic trade. You've spent years pulling vacuums, brazing copper, charging refrigerant, troubleshooting compressors, commissioning supermarket racks, servicing rooftop units, retrofitting walk-ins, working on chiller plants, and showing up for school every winter. You're closing in on your 8,280 work-based hours, you've finished (or you're in) Level 3, and the Certificate of Qualification exam is the last thing standing between you and journeyperson status.

This guide walks you through the last mile. 313A is one of Ontario's compulsory and Red Seal trades, with a complex regulatory layer: ODP (refrigerant handling) certification, TSSA Gas Technician licensing, HRAI training, and a strong union pathway through UA Local 787.

One note up front. Phone STO at 647-847-3000 (toll-free 1-855-299-0028, Mon–Fri 7 a.m.–7 p.m. ET) when a fact has a "verify before you act" caveat.

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Where You Are in the Journey

A 313A apprenticeship in Ontario is 9,000 hours total:

• 8,280 hours of work-based training under a Registered Training Agreement (RTA) with a sponsor employer
• 720 hours of in-school technical training across three levels (240 hours each)

Standard pace is five years. The 313A Apprenticeship Training Standard was updated December 6, 2023 — verify which curriculum applies to your eligibility.

You're at the last mile if:

• You've finished all three school levels (or you're enrolled in Level 3)
• You've logged 7,000+ on-the-job hours
• Your sponsor has been signing off on competencies in your logbook

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313A Scope: What You Do

Your 313A C of Q authorizes you to install, service, repair, and commission:

• Commercial refrigeration — supermarket display cases, walk-in coolers and freezers, ice plants, food processing chillers
• Industrial refrigeration — ammonia plants, ice rinks, cold storage warehouses, food/pharmaceutical process cooling
• HVAC — chillers, package units, split systems, VRF systems, heat pumps, cooling towers
• Heat pumps — air source, ground source, water source — a rapidly growing scope as Ontario decarbonizes residential and commercial heating
• Air conditioning — central AC, split systems, light commercial RTUs (rooftop units)

If your career is residential AC only (single-family heat pumps, central AC), the 313D Residential Air Conditioning Systems Mechanic sub-trade is a separate compulsory trade with a shorter apprenticeship.

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Step 1: Close Out Your Hours and Logbook

The 313A Apprenticeship Training Standard (Dec 6, 2023) is the official competency list. The 313A Trade Report (2024) is STO's blueprint of what gets tested.

Common gaps that hold 313A apprentices up:

• Sponsor signed master units but missed sub-skills
• Specific exposure missing — ammonia if you've done all halocarbon refrigerants, industrial process cooling if you've stayed in commercial, heat pumps if you're a chiller specialist
• Welding/brazing hours undocumented (313A involves substantial brazing work)
• ODP card hours (refrigerant handling) often tracked separately and lost
• Hours from a previous employer never made it to STO when you switched sponsors

How to close gaps:

• For missing competencies: Talk to your sponsor about exposure. UA Local 787 dispatch can rotate members through specialty work for exposure.
• For lost paperwork: Phone STO at 647-847-3000 with your apprentice ID
• For a vanished sponsor: STO has a process for confirming hours when the original employer is unreachable

Push for sign-offs the same week the work is done. RAC service shops cycle through customer accounts fast; sponsors retire or sell.

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Step 2: Confirm Eligibility with Skilled Trades Ontario

Sponsor + TDA submit final confirmation; STO issues an eligibility notice in 4–8 weeks typically.

What triggers eligibility: all three school levels complete and passed, 8,280 OJT hours logged, all competencies signed off, sponsor's final attestation submitted.

If 4–8 weeks turns into 16: phone STO at 647-847-3000.

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Step 3: Book the C of Q Exam — The Actual Portal Flow

The portal: https://portal.skilledtradesontario.ca/, authenticated through My Ontario Account.

Click-by-click:

1. Sign in to the STO Trades Portal
2. Pay the exam fee first ($150 + HST = $169.50)
3. Click Examination at the top of the portal
4. Enter your STO ID number
5. Select your name and exam type
6. Indicate accommodation needs (phone STO directly to arrange)
7. Choose date, time, and test centre
8. Add to cart, review, confirm

The first-attempt fee waiver: Apprentices completing programs on or after January 1, 2025 get the first-attempt fee waived automatically.

STO test centres: Same 22-centre network (Centennial, Durham, Georgian, George Brown, Humber, STO HQ, Algonquin, Fleming, Loyalist, St. Lawrence, Canadore, Collège Boréal, Confederation, Sault, Conestoga, Fanshawe, Lambton, Mohawk, St. Clair). Full list at skilledtradesontario.ca/certification/exam-scheduling/.

Reschedule: Once at no cost with at least 5 business days' notice.

Don't book before you're ready. Rewrite costs $169.50 plus a mandatory 30-day wait.

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Step 4: The Exam — Format and Blueprint

The 313A C of Q exam is a written, computer-based, multiple-choice exam.

Format (per STO's June 2023 Exam Preparation Guide):

• 90–150 multiple-choice questions (4 options each)
• Up to 4 hours
• Pass mark: 70%
• The test centre supplies all materials — calculator, scratch paper, on-screen reference excerpts. Personal calculators, code books, and reference texts are NOT permitted.
• Confirm exact question count and time on your Authorization to Test letter

Red Seal blueprint — 313A is harmonized to the Red Seal Refrigeration and Air Conditioning Mechanic occupational analysis. Confirm the most current 313A-specific blueprint on the 313A Trade Report.

Reference codes that matter most:

• CSA B52 — Mechanical Refrigeration Code (Ontario adopted)
• CSA B149.1 — Natural Gas and Propane Installation Code (gas-fired chillers, water heaters)
• CSA B214 — Hydronic heating systems (heat pump and hydronic integration)
• OBC Part 6 (HVAC and ventilation in buildings)
• OHSA Construction Projects Regulation O. Reg. 213/91
• Ontario Reg. 463/10 — Refrigerants (the regulation under which the ODP card is mandated)
• CSA W47.1 — Welder qualification (for brazing/welding)

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Step 5: How to Actually Prepare

There's no STO-published 313A-specific exam prep guide. Read the Trade Examinations in Ontario Exam Preparation Guide first.

Free or near-free

• Your apprenticeship in-school binders and textbooks
• The 313A ATS (Dec 6, 2023) and 313A Trade Report
• The Red Seal RAC Mechanic occupational analysis
• HRAI training catalogue: hrai.ca/hrai-training-courses
• JTAC-787 training resources for UA members — see Union Pathway below

Paid — verified courses

• Mohawk College — Refrigeration and Air Conditioning Systems Mechanic 313A: mohawkcollege.ca/programs/skilled-trades/refrigeration-and-air-conditioning-systems-mechanic-313a
• Centennial College — Refrigeration & Air Conditioning Systems Mechanic: centennialcollege.ca/programs-courses/full-time/refrigeration-air-conditioning-systems-mechanic
• Conestoga College — 313A apprenticeship streams (conestogac.on.ca/apprenticeship)
• Skilled Trades Academy — 313A / G1 / G2 / G3: getatrade.com/courses/

Where 313A apprentices actually fail

• Refrigeration cycle thermodynamics — pressure-enthalpy diagrams, superheat/subcool, capacity calculations
• Electrical/controls — three-phase motor circuits, control wiring, troubleshooting compressor starts (consistently one of the highest-failure areas)
• CSA B52 navigation — refrigeration plant rules, machine room requirements, refrigerant safety classifications
• Specialty refrigerants — CO2 (R-744) transcritical, hydrocarbon (R-290), and A2L refrigerants are increasingly tested as the industry transitions

Study tactics that work

• Drill CSA B52 — refrigerant classifications (A1/A2/A2L/A3/B1/B2L), machine room requirements, charge limits
• Practice the math — refrigeration cycle calculations, superheat/subcool, refrigerant charge calculations, electrical Ohm's law and three-phase fundamentals
• Take timed practice exams — if you can't finish at 70%+ under time pressure, you're not ready
• Group study with other 313A apprentices, especially through your UA local or college program

What doesn't work

• Cramming. A week covers about 10% of what's tested.
• Memorizing answers from sample exams. STO refreshes the question pool.
• Skipping ammonia / industrial refrigeration if you've stayed in commercial. Industrial questions appear regardless.
• Skipping electrical/controls — this is consistently one of the highest-failure areas.

How long to study: Most 313A apprentices spend 4–8 weeks of focused review (10–20 hours/week).

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Step 6: Exam Day

What to bring: Government-issued photo ID, printed Authorization to Test letter, a pen.

What's provided: Computer terminal, on-screen reference materials, calculator (test centre supplied), scratch paper, English/French dictionaries.

What you can't bring: Phone (locked in a locker), books/notes, smartwatch, any external code book, personal calculators.

On the screen: One question at a time, four multiple-choice answers, flag-for-review button, running clock, question counter.

Result: Pass/fail on screen immediately when you submit. Detailed unit-level scoring follows by mail or email.

If you fail: 30-day mandatory wait, $169.50 rewrite fee, unit-level scoring with your fail letter.

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Step 7: After You Pass

You're a journeyperson RAC mechanic. What happens next:

What you'll receive (4–8 weeks after passing):

• Certificate of Qualification (313A) — physical certificate mailed to your address on file
• Apprenticeship Completion Certificate
• Red Seal endorsement — automatic for 313A at a 70%+ exam score (Red Seal RAC Mechanic)

What changes immediately:

• You're legally allowed to work as an unsupervised RAC mechanic in Ontario
• Your wage rate jumps to journeyperson scale
• You can sponsor 313A apprentices yourself
• You should already hold an ODP card (most apprentices get this in Year 1) — if you don't, get one immediately
• You can write the TSSA G3 gas technician exam if you don't already hold it
• With Red Seal, you can work in any other Red Seal province (most provinces require registration with the destination apprenticeship authority before performing compulsory-trade work)

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Step 8: The ODP Card (Refrigerant Handler Certificate)

Mandatory. Under Ontario Regulation 463/10, anyone who removes, discharges, handles, or disposes of CFCs, HCFCs, HFCs, and other halocarbon refrigerants must hold a Certificate to Handle Refrigerants — the ODP card.

• Issued by HRAI on behalf of Ontario's Ministry of Environment, Conservation and Parks (MECP)
• Ontario program page: ontario.ca/page/certificate-handle-refrigerants
• HRAI ODP/ODS course page: hrai.ca/odp-ods-online-program
• HRAI renewal: hrai.ca/odp-card-renewal

Format: 1-day approved course. 75% pass mark. Valid 5 years, then renewal through HRAI before expiry. If your card lapses, you must retake the full course.

What the ODP card does NOT cover:

• Hydrocarbon refrigerants (HC, e.g., R-290 propane) — separate awareness training required
• A2L (mildly flammable) refrigerants — HRAI offers a separate A2L / Low GWP Online Course

As Ontario's HVAC market transitions to lower-GWP refrigerants (R-32, R-454B, R-290), expect additional refrigerant-handling certifications to become standard. The HRAI Low GWP / A2L course is the de facto industry credential.

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Step 9: TSSA Gas Technician Ladder (Almost Mandatory for 313A)

If your work involves gas-fired equipment (gas-fired chillers, water heaters, boilers, gas furnaces, gas-fired RTUs), you need a TSSA Gas Technician certificate. Most successful 313A journeypersons hold a G2 by Year 2 of journeyperson work.

The ladder:

Apply through: TSSA Client Portal. Procedures: TSSA Gas/Oil Burner Technician Procedures and Policies.

TSSA exam fee: $225 per level. Pass mark: 75%. Class attendance: 80%.

Where to train:

• George Brown — TSSA Gas Technician 2: coned.georgebrown.ca/courses-and-programs/tssa-gas-technician-2
• Skilled Trades Academy: getatrade.com/courses/
• Mohawk, Conestoga, Algonquin, Centennial — all run TSSA G3/G2/G1 programs through continuing education
• JTAC-787 runs TSSA programs for UA members

A 313A + ODP card + G2 + (eventually) G1 is the standard ticket stack for journeyperson commercial RAC mechanics.

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Step 10: HRAI Programs and Industry Specialty

The Heating, Refrigeration and Air Conditioning Institute of Canada (HRAI) runs the industry's training programs. HQ at 2350 Matheson Blvd East, Suite 101, Mississauga ON L4W 5G9.

Verified HRAI programs relevant to 313A:

• ODP/ODS Online Program (hrai.ca/odp-ods-online-program)
• A2L / Low GWP Online Course (hrai.ca/flammable-online-course) — increasingly required as the industry transitions to A2L refrigerants
• Residential Mechanical Ventilation Design
• Heat Loss / Heat Gain calculations
• Refrigerant Management
• Full catalogue: hrai.ca/hrai-training-courses

Industry specialty paths post-313A:

• Ammonia / industrial refrigeration — RETA (Refrigerating Engineers and Technicians Association) Certified Industrial Refrigeration Operator (CIRO) is the recognized credential for ammonia plant work
• Heat pumps — Ontario residential decarbonization is driving rapid heat pump growth; HRAI heat pump training and manufacturer-specific (Mitsubishi, Daikin, LG, Carrier) certifications open premium retrofit work
• CO2 (R-744) transcritical — supermarket refrigeration is rapidly moving to CO2; specialty manufacturer training is available through Hillphoenix, Hussmann, Carnot
• VRF (Variable Refrigerant Flow) — manufacturer-specific certifications (Mitsubishi, Daikin, LG, Samsung) for premium commercial work
• Building automation and controls — Tridium/Niagara, Siemens, Honeywell, Distech — overlap with RAC service

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Step 11: Going Independent — RAC Service Contracting

RAC service contracting is one of the better paths to self-employment in Ontario mechanical trades. Service work is recurring, recession-resistant, and high-margin. The path:

1. Hold your 313A C of Q ✅ (completed via this guide)
2. Hold your ODP card (mandatory)
3. Add TSSA G2 (mandatory if doing any gas work)
4. Build journeyperson experience — 2–5 years before going independent
5. Add specialty manufacturer certifications (heat pumps, VRF, CO2, controls) for premium service work
6. Carry CGL insurance — typically $2,000,000 minimum for residential, $5M+ for commercial
7. Carry equipment, tool, and vehicle insurance
8. Register a business — incorporate or sole proprietorship
9. Register WSIB — mandatory for any RAC employer
10. Build customer relationships — commercial property managers, restaurant chains, supermarkets, light industrial, residential service customers

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Continuing Competency

• ODP card renewal every 5 years (mandatory; lapsed cards require retaking the full course)
• TSSA gas certificate renewal — confirm renewal cycle on the TSSA Client Portal
• A2L / Low GWP refrigerant training — increasingly required as the industry transitions
• Specialty manufacturer recertifications — heat pumps, VRF, CO2 transcritical typically annual
• CSA B52 code update training — periodic revisions to refrigeration code
• HRAI continuing education — heat loss/gain, refrigerant management, design

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The Union Pathway (UA Local 787 / JTAC-787)

The dominant union for RAC mechanics in Ontario is UA Local 787 — a province-wide RAC-specific UA local. The training centre is JTAC-787 (Joint Training and Apprentice Committee).

UA Local 787:

• HQ: 419 Deerhurst Drive, Brampton, ON L6T 5K3
• Phone: 905-790-1019
• Ottawa office: 1570 Liverpool Court, Unit 6, Ottawa K1B 4L2

JTAC-787:

• Phone: 905-790-9662
• Email: [email protected]
• Programs: 313A apprenticeship, journeyperson upgrades, ODP card, TSSA G3/G2/G1, A2L refrigerant training (in partnership with ESCO Institute), heat pump training, CO2 transcritical, manufacturer-specific certifications
• One of the few HVACR-specific training centres in Canada
• No-cost training in partnership with Ontario MLITSD for many programs

For non-union 313A apprentices: You can join Local 787 after qualifying. The local will assess your experience and place you at the appropriate journeyperson rate. Initiation fee and dues apply.

Why union pathway matters: UA Local 787 dispatch covers a large share of commercial and industrial RAC work in Ontario. Hospital, university, large commercial, supermarket, and industrial process customers often spec union RAC contractors. JTAC-787 continuing education is one of the highest-quality programs in North America for journeyperson RAC mechanics.

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Provincial and Federal Incentives — Verified May 2026

Active in 2026:

• Ontario Tools Grant: $600 for construction trades (313A qualifies)
• Federal Tradesperson's Tools Deduction — up to $1,000 federal deduction at tax time, 2026 base $1,501
• Canada Apprentice Loan — up to $4,000 interest-free per period of technical training (Red Seal trades — 313A qualifies)
• Apprenticeship Job Creation Tax Credit (employer-side) — 10% of wages, max $2,000/year, first 2 years, Red Seal only
• Achievement Incentive Program (employer-side) — up to $17,000 per apprentice

No longer claimable:

• Federal Apprenticeship Completion Grant ($2,000) — CLOSED March 31, 2025. Replaced by Team Canada Strong (not yet active as of May 2026).

Provincial summary: ontario.ca/page/financial-supports-apprentices-and-sponsors.

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Common Mistakes to Avoid

1. Booking the exam before you're ready. First attempt is fee-waived for apprentices completing on/after Jan 1, 2025; rewrite costs $169.50 plus a 30-day mandatory wait.

2. Letting your ODP card lapse. It's mandatory under O. Reg. 463/10. A lapsed card means re-taking the full course, not just renewing.

3. Letting your logbook fall behind. Service shops cycle through accounts fast.

4. Underestimating CSA B52. The refrigeration code is heavily tested.

5. Skipping electrical/controls. Consistently one of the highest-failure areas on the 313A exam.

6. Cramming. A week covers about 10% of what's tested.

7. Treating the C of Q as the finish line. ODP card, TSSA G2/G1, A2L, CO2, VRF, heat pump, controls — those are what separate journeyperson RAC mechanics who command premium rates from those who stay at base scale.

8. Forgetting Red Seal. A 70%+ pass on the 313A C of Q automatically confers Red Seal. Western Canada and northern industrial actively recruit Red Seal RAC mechanics.

9. Not adding TSSA G2. A 313A without G2 is locked out of any gas-fitting work. Plan to add G2 within your first journeyperson year.

10. Underestimating heat pump growth. Ontario's residential decarbonization push is accelerating heat pump installation. RAC mechanics with heat pump specialty certifications are in chronic demand.

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What This Costs (Summary, May 2026)

Apply against the Ontario Tools Grant ($600), the Tradesperson's Tools Deduction (federal), and the Canada Apprentice Loan ($4,000 interest-free per training period).

If you're a Local 787 member, JTAC-787 covers exam prep, ODP, TSSA training, and most specialty certifications.

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What Happens Next

You have your 313A. You're a Red Seal-endorsed journeyperson RAC mechanic. The most common next steps:

• Stay employed at a RAC service contractor. Build experience, save money, stack tickets.
• Add your ODP card (if you don't already hold one) — mandatory under O. Reg. 463/10
• Add TSSA G2 within Year 1 — mandatory for any gas-fitting work
• Add HRAI A2L / Low GWP training — increasingly required
• Pursue specialty manufacturer certifications — heat pump, VRF, CO2 transcritical
• Join UA Local 787 (if you weren't already) — JTAC-787 continuing education is one of the best in North America
• Pursue Red Seal opportunities elsewhere. Western Canada, oil sands, prairie infrastructure all recruit Ontario Red Seal RAC mechanics
• Go independent. RAC service contracting is one of the better paths to self-employment in Ontario mechanical trades

If independence is the goal, the next reads are in Idea to First Bid:

• Guide 1: Incorporation
• Guide 2: CRA Registration
• Guide 3: WSIB & Provincial Registration
• Guide 5: Insurance

Refrigeration and air conditioning is one of the most reliable specialty mechanical trades in Ontario — service work is recurring, recession-resistant, and growing as buildings electrify and decarbonize. Your C of Q just put you in position to build that career.