Refrigeration & AC Systems Mechanic · Red Seal 313A
Five 313A practice test questions, answers included.
Five questions from five different work activities — recall, procedural and critical-thinking, the way the exam is built. Pick an answer, then open the explanation. Every question in the bank explains all four options, not just the right one.
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45 free 313A questions in all
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An R-134a medium-temperature walk-in cooler with a TXV runs continuously. Readings: suction 35 kPa (5 psig, saturated −3 °F); suction line 40 °F; discharge 915 kPa (133 psig, saturated 104 °F) at 29 °C (85 °F) ambient; liquid line 92 °F; sight glass clear; no temperature drop across the drier or LLSV; opening the TXV adjustment fully makes no change. Which cause fits?
- A plugged liquid-line filter-drier
- Low refrigerant charge
- The TXV power element (bulb) has lost its charge
- The TXV bulb is loose and sensing warm air
Show the answer
C. Correct. Superheat is 40 − (−3) = 43 °F with normal 12 °F subcooling, a clear sight glass and no restriction upstream: liquid reaches the valve but the valve will not open, and adjustment has no effect. A bulb that has lost its charge closes the valve. Replace the power element or valve.
Source: Red Seal Occupational Standard, sub-task F-14.01
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On an R-134a reach-in cooler the suction pressure at the evaporator outlet is 22 psig (152 kPa), which the P/T chart shows as 24 °F saturated. The suction line at the same point measures 36 °F. What is the evaporator superheat?
- 2 °F (1.1 K)
- 12 °F (6.7 K)
- 14 °F (7.8 K)
- 24 °F (13.3 K)
Show the answer
B. Correct. Superheat = suction-line temperature − saturated suction temperature from the P/T chart = 36 − 24 = 12 °F, a 6.7 K difference. The pressure is only the way into the chart. For a zeotropic blend (an R-4xx refrigerant) the chart's dew-point column would be used; R-134a is a pure fluid with a single saturation column.
Source: Red Seal Occupational Standard, sub-task E-11.03
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You are brazing a copper suction line to the steel stub on a semi-hermetic compressor. Which filler and flux selection is correct?
- A BAg silver-bearing alloy with a suitable brazing flux
- A BCuP copper-phosphorus alloy without flux, as on copper-to-copper joints
- A BCuP copper-phosphorus alloy with flux to compensate for the steel
- A 95/5 tin-antimony solder with paste flux, since the joint is on the low side
Show the answer
A. Correct. Copper to steel (or to brass) is joined with a BAg silver alloy and flux. The flux removes oxides from the steel and lets the alloy wet it. The same rule applies to copper-to-brass valves. BCuP alloys are for copper to copper only.
Source: Red Seal Occupational Standard, sub-task B-6.01
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While confirming the layout of a walk-in cooler, the mechanic checks the proposed unit-cooler (evaporator) location. Which placement is correct?
- Directly above the door so infiltrating warm air is cooled first.
- Close beside the door so the door-frame heater does less work.
- At the lowest point in the box so the condensate drain run is shortest.
- On the wall away from the door, throwing down the long axis toward it.
Show the answer
D. Correct. The coil sits away from the door, typically on the far wall, its fans throwing the length of the box toward the door or down an aisle, as the manufacturers recommend, so product is covered evenly and the coil is not sitting in the air that enters when the door opens. The maker's clearance behind the unit keeps the return-air path open, and the drain needs its slope and a trap outside the box (heat-traced in a freezer).
Source: Red Seal Occupational Standard, sub-task D-9.01
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During a site survey for a new 10-ton condensing unit the only supply available is a 208 V three-phase panel. The selected unit's nameplate reads 575 V three-phase, MCA 14 A. What must the installation plan do about this?
- Connect it as is, since motors are rated to operate within ±10 % of nameplate voltage.
- Order a single-phase 240 V version and run it from two legs of the 208 V panel.
- Feed the unit through a variable frequency drive so the drive corrects the voltage.
- Re-select a 208/230 V unit, or have a step-up transformer provided for the 575 V unit.
Show the answer
D. Correct. Utilities available on site are a planning input: either match the equipment to the 208 V service or plan a transformer sized for the unit's MCA (with the electrician and the AHJ). Either way the decision is made before ordering, because the electrical service is part of the equipment selection.
Source: Red Seal Occupational Standard, sub-task C-7.01
Want ten more with every option explained? Free 313A practice questions — no account, no email, printable. With five more on each exam block page below, that makes 45 free 313A questions in all.
The 313A exam at a glance
How many questions are on the 313A Red Seal exam?
The Red Seal Refrigeration and Air Conditioning Mechanic (313A) exam has 125 multiple-choice questions, a 4-hour writing time and a 70% pass mark, which is 88 correct answers. The questions cover six major work activities, and 50 to 60 percent are procedural and application questions. Sources: the Red Seal Program's exam information page and Exam Preparation Guide, checked October 21, 2026.
Question mix — weighted to the blueprint
More than half the paper asks you to carry out a procedure — the largest procedural share of any mechanical trade on this site. Only one question in four asks you to state a fact. The rest asks you to take superheat and subcooling from a gauge set, complete a charge, set a control, work a load from the formula sheet, or reason from a full set of readings to the one cause that fits — which is exactly where recall-only question banks leave you exposed.
The full 313A practice exam
Know your Refrigeration & AC score before exam day.
Free, Red Seal–style practice for the 313A Refrigeration and Air Conditioning Mechanic certification. Every test is weighted to the official exam blueprint — more than half procedure, the rest recall and critical thinking — so your score shows where you stand on each part of the exam.
What the 313A covers
Six major work activities.
The occupational standard groups the trade into six major work activities, 15 tasks and 57 sub-tasks. The question counts below are the official blueprint weightings — our 550-question bank is built to that same map, with every sub-task covered.
- A
Performs common occupational skills · 13 questions
Safety-related functions and lock-out, tools and equipment (brazing, recovery, evacuation, charging, diagnostic and rigging gear), organizing work from drawings and documentation, and communication and mentoring. Free block A questions: safety, tools and trade skills →
- B
Performs routine trade activities · 19 questions
Work site preparation and materials handling, then the core trade activities: brazing and soldering, leak and pressure tests, evacuation, refrigerants, gases and oils, field wiring, and sealants and adhesives. Free block B questions: brazing, pressure testing and evacuation →
- C
Plans installation · 18 questions
Planning HVAC/R systems (11 questions) and control systems (7): verifying parameters and requirements, selecting equipment and components, determining placement, and material take-off. Free block C questions: system design and load calculation →
- D
Performs installation · 26 questions
Installing HVAC/R systems (16 questions): confirming layout, assembling and placing equipment, fasteners and hangers, piping and tubing, and the holding charge. Installing control systems (10): placing and connecting components. Free block D questions: refrigerant piping and control wiring →
- E
Performs commissioning · 21 questions
HVAC/R systems (13 questions): pre-start-up checks, start-up, completing the charge, and setting up primary and secondary components. Control systems (8): start-up checks and verifying or setting operating parameters. Free block E questions: start-up, charging and control setup →
- F
Performs maintenance and service · 28 questions
Maintaining HVAC/R systems (8 questions), servicing them — troubleshooting and repair (11) — and maintaining and servicing control systems (9): inspection, troubleshooting, calibrating operating and safety controls, and repair. Free block F questions: maintenance, service and troubleshooting →
Where our numbers come from
Every question, anchored to the standard.
HVAC/R practice banks quietly go wrong in two ways: a superheat, subcooling or charge figure that belongs to one manufacturer presented as a universal number, and formulas tested as memory when the exam hands you a formula sheet. Every question in our 313A bank is anchored to a sub-task of the occupational standard and verified against it, with all four options explained. The formula sheet and acronym list are provided at the exam sitting — Btuh = 4.5 × CFM × ΔH, 1.08 × CFM × ΔT, 500 × USGPM × ΔT, psia = psig + 14.7, 12 000 Btuh per ton — so our airflow, water-flow and load questions are written to be worked from that sheet, and we never test recall of the formulas themselves. Where a value is genuinely set by the manufacturer, such as a subcooling target or a nameplate charge, the question gives it in the stem or tests the method and the relationship instead of inventing a figure. The question counts above are the Red Seal Program's own exam breakdown for Refrigeration and Air Conditioning Mechanic, and every question is mapped to a sub-task of the Red Seal Occupational Standard. The Red Seal Program has published a 2024 standard and says new exams based on it are under development; until then the current exam and this bank follow the 2019 standard. For what each block covers and where to spend your study time, read the 313A exam guide. Read how our questions are made.
Tools for this exam: the free refrigerant PT chart, no account needed.
Edited by Trevor Mulder · Last checked against the Red Seal Program's published exam information.
Why practice scores mislead
You can ace recall and still fail the 313A.
Most question banks drill what you can recall, because recall questions are cheap to write. On the 313A that covers 20 to 30 percent of the paper at best. The other 70 to 80 percent asks you to do the job: procedural questions that ask you to take superheat and subcooling from a gauge set and a P/T chart, charge a blend as liquid, set a low-pressure control for pump-down or braze under a nitrogen purge, and critical-thinking questions that hand you a full set of readings and ask which one cause fits. That gap is why people walk in confident and walk out surprised. TicketPrep weights every test to the published blueprint, so a weak block here is a weak block there.
How TicketPrep prepares you
Built like a study tool, not a quiz app.
Weighted to the blueprint
Every test matches the published 313A weightings — recall, procedure and critical thinking in the proportions the published exam breakdown sets.
Every answer explained
Learn why the right answer is right — and why each of the other three is wrong. That's where the learning happens.
Timed mock exams
Full-length tests that match the real 125-question count and 4-hour limit, so exam day feels familiar.
Know your weak areas
Your score broken out by work activity, so you always know which block to drill next.
313A questions
Before you start.
How many questions are on the 313A Red Seal exam?
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What does the 313A exam cover?
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Other trades
More Red Seal practice exams.
Working on residential systems only in Ontario? The 313D Residential Air Conditioning Systems Mechanic licence is a separate Ontario exam, not a Red Seal one: 313A vs 313D explains which you need.