Question Bank Updates

How corrections are made

In September 2026 all eleven question banks were audited. Each finding was put to a reviewer whose job was to defend the question, and most of the findings that survived were checked again by a second, independent reviewer.

• Wrong or disputable answer: the question is removed. It is not edited until it passes. Removed questions leave the free quiz, the free pages and the PDFs.
• Wrong explanation: the explanation is corrected. The corrected line is written from a source the corrector opened and is checked by an independent verifier before it goes live. The question, its options and its answer stay the same.
• New questions go live only after a break attempt and a source check. They replace a question that tested the same fact as another, or bring a bank back to its official exam length. A reviewer tries to break each one and its source is checked independently; candidates that fail are dropped, not revised.
• Findings that are not defects are dismissed. Those questions are left as they were.

Later corrections are added to this page with their date. To report an error, use the Contact page.

Jump to: Summary · By trade · Exam facts and site pages · PDF files

Summary: September 2026 audit

Bank size is before → after the audit. Explanations fixed: 58 come from the audit list (57 on 2026-09-13, one on 2026-09-14). Seven more were found while re-checking related questions: one 313A key concept on 2026-09-13 and six 421A explanations on 2026-09-14.

Replaced questions keep their place in the bank and get a new question on a different fact. Dates are the day a change went live on this site.

By trade

421A · 310T · 310S · 306A · 309A · 442A · 313A · 420B · 308A · 456A · Gasfitter

421A Heavy Duty Equipment Technician

Bank size: 421 before the audit, 406 after.

• 2026-09-13 15 questions removed. Three taught the torque-converter stall test backwards, or offered two defensible answers built on that rule; twelve more had two defensible answers or stated a diagnostic rule the wrong way round.
• 2026-09-13 12 explanations or key-concept lines corrected.
• 2026-09-14 7 explanations corrected in the hybrid and electric equipment questions: one from the audit list and six found when the rest of that block was re-checked. No question, option or answer changed.

310T Truck & Transport Mechanic

Bank size: 165 before the audit, 161 after.

• 2026-09-13 4 questions removed: one had two defensible answers on spring-brake apply pressure, one described a DEF inducement stage that does not exist, and two more were removed after two independent reviews.
• 2026-09-13 4 explanations corrected, including one that gave an out-of-date US speed limit for DEF-fault engine derate; it now points to the engine maker's service information.
• 2026-09-13 2 questions that tested the same fact as another question were replaced with new questions on different facts.

310S Automotive Service Technician

Bank size: 139 before the audit, 139 after.

• 2026-09-13 No questions removed. 1 explanation corrected, and 1 question that tested the same fact as another question was replaced with a new question.

306A Plumber

Bank size: 135 before the audit, 130 after.

• 2026-09-13 5 questions removed: one asked about a wall-hung water closet and answered with the floor-mount procedure; four more were removed after two independent reviews.
• 2026-09-13 3 explanations corrected, and 1 duplicate question replaced with a new question.

309A Construction Electrician

Bank size: 135 before the audit, 131 after.

• 2026-09-13 4 questions removed: one mixed CSA Z462 PPE categories with an incident-energy analysis, one gave an unsupported conductor size for luminaire wiring, one more was removed after two independent reviews, and one after the two reviewers disagreed and a third review found the question's premise wrong and a second option defensible.
• 2026-09-13 5 explanations corrected, and 4 duplicate questions replaced with new questions.

442A Industrial Electrician

Bank size: 135 before the audit, 130 after.

• 2026-09-13 5 questions removed: one had two defensible answers, and four more were removed after two independent reviews.
• 2026-09-13 7 explanations corrected.

313A Refrigeration & Air Conditioning Mechanic

Bank size: 116 before the audit, 115 after.

• 2026-09-13 1 question removed: it had two defensible answers.
• 2026-09-13 1 explanation corrected, and one key concept that gave the wrong reference point for R-407C superheat now reads dew point for superheat and bubble point for subcooling.
• 2026-09-13 1 duplicate question replaced with a new question on reading superheat from the dew column of a zeotropic blend's pressure-temperature chart.

420B Ironworker (Generalist)

Bank size: 120 before the audit, 121 after.

• 2026-09-13 3 questions removed: one gave a single minimum safety factor for all rigging hardware, which does not hold for chain slings, and two more were removed after two independent reviews.
• 2026-09-13 5 explanations corrected, 1 duplicate question replaced, and 4 new questions added.

308A Sheet Metal Worker

Bank size: 120 before the audit, 120 after.

• 2026-09-13 3 questions removed: one relied on a confined-space regulation that excludes the work settings the question described, and two had two defensible answers.
• 2026-09-13 5 explanations corrected, 1 duplicate question replaced, and 3 new questions added.

456A Welder

Bank size: 120 before the audit, 125 after.

• 2026-09-13 1 question removed: the two independent reviewers disagreed, and a third review found a second option defensible (a neutral flame for aluminum).
• 2026-09-13 6 explanations corrected, and 6 new questions added, which brings the bank to the length of the official exam so the full mock exam runs at real exam length.

Gasfitter (Class A)

Bank size: 112 before the audit, 110 after.

• 2026-09-13 2 questions removed after two independent reviews.
• 2026-09-13 8 explanations corrected.

Exam facts and site pages

• 2026-10-01 Information pages: an unsourced figure for how many Canadians hold a Red Seal endorsement was replaced with the Statistics Canada count of 2024 trade certificates issued with a Red Seal endorsement. 420B is named Ironworker (Generalist) throughout; Structural/Ornamental Ironworker (420A) and Reinforcing Rodworker (452A) are separate Red Seal trades. The number of Red Seal trades is given as 54, the red-seal.ca list as of October 2026, instead of “over 50”.
• 2026-10-01 llms.txt, the summary file for AI assistants, now says what the 313A and 420B pages already said: British Columbia already uses the new Red Seal exams for these two trades, while red-seal.ca still lists them as under development.
• 2026-09-30 Wages on 14 salary and career pages and 2 general guides: ranges without a source were replaced with Government of Canada Job Bank figures (low, median and high wage by occupation code, region and reference year), or rewritten without a number where no public source exists.
• 2026-09-30 Search markup on 8 common-mistakes pages: 24 question-and-answer entries had been cut off mid-sentence. They were rebuilt in full from each page's visible text.
• 2026-09-30 Exam conditions: pages no longer call the exams “closed-book”. You cannot bring your own notes or reference books, but the reference material an exam needs, such as a formula sheet or acronym list, is supplied.
• 2026-09-30 Mock exam descriptions on several pages said the practice mocks follow the official exam proportions. They now say the mocks draw from every topic in the practice bank. Statements about how candidates do on the exam, which no published data supports, were removed from guide pages, and four page descriptions that had been cut off mid-sentence were completed.
• 2026-09-29 Exam specifications, fees and wages were re-checked against primary sources (red-seal.ca and provincial exam pages, provincial fee schedules and Government of Canada Job Bank): 1,338 stated facts checked, 660 corrections on 82 pages. They include the edition of the Red Seal Occupational Standard named for each trade, the new 313A exam on the 2024 standard, official Major Work Activity counts in place of earlier splits that were not Red Seal's (420B and 421A), exam fees in four provinces, and wage figures that now give their Job Bank occupation code, range, median and data year.
• 2026-09-29 Topic areas: wording on several pages and on the PDF covers presented the banks' topic areas as set by the official exam weightings. They are not. The topic areas are this site's own study groupings, not one-to-one with the official Major Work Activities, which each trade's quiz page lists from red-seal.ca. The wording was removed.
• 2026-09-22 Three exam statistics that cannot be derived from Red Seal's published data were removed or rewritten (Gasfitter, 420B and 442A guides). Four study-tip boxes whose headings suggested exam-result data, which Red Seal does not publish, were renamed.
• 2026-09-15 The exam format guide's search markup gave the wrong exam length for three trades, and three guides gave a wrong time per question. Both were corrected.
• 2026-09-14 The trades guide still showed the question counts from before the audit on all eleven trade cards; they were restated. Three exam-tip guides gave an exam length that contradicted the same page, and were corrected.

PDF files

• 2026-10-03 The printable question banks for ten trades gained a Part 4: full-length practice exams made only from questions already in that bank, each the size and time limit of the trade's official exam (two papers for 421A, one for each of the other nine). No question, option, answer or explanation was changed, added or removed, and Parts 1–3 keep their numbering. 313A has no Part 4, because its 115-question bank is smaller than its 125-question official exam. The shop files were replaced the same day.
• 2026-09-30 The printable banks and revision notes delivered by the shop were replaced with the rebuilt files described below, for all eleven trades.
• 2026-09-29 Revision notes: the number in brackets after each line, such as [Q12], is meant to be that question's number in the trade's Complete Question Bank. The notes printed the site's internal question id instead, so in every trade most references pointed at the wrong question. The notes were rebuilt with every reference checked against the bank. The same rebuild removed the topic-area wording above from the covers of all 33 PDFs (free mock exams, printable banks and revision notes); the free mock exams on this site were replaced the same day.
• 2026-09-14 The printable PDFs in the shop were rebuilt from the corrected banks and replaced.
• 2026-09-13 The free 50-question mock exam PDFs were rebuilt from the corrected banks. Six of them had contained a question removed in the audit.

Every question in the printable PDFs is also free to read on this site, and the PDFs are rebuilt from the same banks after a correction.