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Free worked lessons and practical study guides for G3, G2, electrical, and other trade learners. Start with a question. Leave with a method.
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4 lessons · 36 articles
Try free practice →Learn it. Work it through.
Open access · no signupOhm’s law: see the circuit, solve the question
Work through a 24 V circuit, change voltage and resistance, and check your answer with units.
Unit conversions without the guessing
Use unit cancellation for length and power, and see why temperature conversions need an extra step.
Build a codebook lookup routine for G3 and G2 study
Practise finding a topic, checking its scope, reading table notes, and recording a useful reference.
Turn a wrong answer into your next study task
Diagnose a missed question, write a useful correction, and test whether you can repeat the reasoning.
From the CodeSafe article library
All articles →How to Choose a Gas Technician School in Ontario
Compare Ontario gas technician programs by accreditation, practical training, total cost and schedule before committing to a G3 or G2 course.
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Carbon Monoxide vs Natural Gas: What Is the Difference?
Carbon monoxide and natural gas are different. Learn why odour, CO alarms and fuel-gas detection cannot be treated as interchangeable warning systems.
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Vent Connector, Chimney, Flue and Vent: A Student's Terminology Guide
Learn how a vent connector, chimney, flue and termination differ, then practise reading a labelled appliance diagram without guessing from appearance.
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Gas Pressure Units: kPa and Inches of Water Column Explained
Read pressure units correctly, distinguish kPa from Pa and convert conventional inches of water column without mistaking an example for an operating target.
By CodeSafe Canada
Gas Appliance Input, Output and Efficiency: How to Read the Numbers
Learn the difference between gas appliance fuel input, useful heating output and AFUE, with original classroom examples and specification-reading checks.
By CodeSafe Canada
Gas Technician Job Interview Questions: Prepare Useful, Honest Answers
Prepare for a gas technician interview with seven original prompts, honest answer structures and questions about supervision, tools and first-month expectations.
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TSSA Gas Technician Certificate Renewal: A Practical Ontario Checklist
Keep your gas technician renewal organized: check the certificate, invoice, payment handoff and final status, and know where to ask about a lapsed certificate.
By CodeSafe Canada
G3 and G2 Exam Accommodations in Ontario: How to Prepare Your Request
Organize a TSSA exam accommodation request, understand the documentation conversation and confirm arrangements before scheduling your G3 or G2 examination.
By CodeSafe Canada
433A Millwright Red Seal Exam Structure and Study Guide
Explore Ontario's 433A Millwright Red Seal question breakdown and current exam outline, with practical exercises for reading dimensions and evaluating study evidence.
By CodeSafe Canada
310T Truck and Coach Exam Structure: Outline and Source Check
See the published 310T topic map, the official 135-versus-150 question discrepancy, and a practical coverage ledger for planning study beyond familiar work.
By CodeSafe Canada
310S Automotive Service Technician Exam Structure and Study Map
Read the published 310S automotive exam topic breakdown, understand the official source-status caveat, and build practice sessions around evidence of your gaps.
By CodeSafe Canada
442A Industrial Electrician Exam Structure and Study Guide
Understand Ontario's 442A Industrial Electrician exam structure, current topic allocation and question styles, with original control-reading and calculation exercises.
By CodeSafe Canada
309A Red Seal Exam Structure: Questions and Study Map
Understand the current 309A Construction Electrician exam outline, Ontario timing and passing grade, then turn the topic allocation into a practical study map.
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G3 Exam Structure in Ontario: Format, Coverage and Booking
Understand Ontario G3 exam format, curriculum coverage, permitted references and booking steps, with current TSSA sources and a practical way to prepare.
By CodeSafe Canada
G2 Exam Structure in Ontario: Understand the Scope Before You Study
Plan G2 preparation around verified TSSA examination information, curriculum coverage and reference rules, while keeping booking and study progress separate.
By CodeSafe Canada
313A Exam Structure: Refrigeration and Air Conditioning
Explore the current 313A Red Seal question allocation, Ontario exam timing and passing grade, with original study exercises and clear distinctions from 313D and gas exams.
By CodeSafe Canada
306A Plumber Red Seal Exam Structure and Study Guide
Learn the current 306A Plumber Red Seal question breakdown, Ontario timing and passing grade, plus practical ways to review diagrams, calculations and weak topics.
By CodeSafe Canada
What to Expect When Starting Gas Technician Work in Ontario
Prepare for your first gas technician role in Ontario with practical questions about supervision, daily assignments, customer communication, tools, and work logistics.
By CodeSafe Canada
Starter Tools for Gas Technicians in Ontario: What to Buy First
Build a practical starter-tool list for gas technician work in Ontario. Compare hand tools, documentation supplies, PPE, and specialist instruments before buying.
By CodeSafe Canada
TSSA Fuels Contractor Registration: An Ontario Startup Guide
Plan your Ontario fuels contractor application with a clear checklist for business details, technician records, portal submission, current fees and ongoing responsibilities.
By CodeSafe Canada
A Four-Week G2 Exam Study Plan You Can Adjust
Build an adjustable four-week G2 revision schedule around your course coverage, available time, targeted module practice, and useful checks of understanding.
By CodeSafe Canada
Turn a Free G3 Practice Test into Your Next Study Plan
Use CodeSafe's 30-question G3 trial with a simple confidence log. Separate guesses from confident mistakes, compare topic counts, and choose your next study task.
By CodeSafe Canada
Module Practice or a Mock Exam: Which Should You Choose?
Choose module practice or a mock exam based on the question your study needs to answer, and read practice scores alongside familiarity, hints, and conditions.
By CodeSafe Canada
Moving from G3 to G2: Build a Stronger Study Routine
Carry useful G3 foundations into G2 study with a practical transition routine, clearer explanations, and a separate check of the requirements for your pathway.
By CodeSafe Canada
Your Final-Week Gas Technician Exam Checklist
Use this final-week G3 and G2 checklist to prioritise remaining study, verify your own exam arrangements, and prepare without relying on another practice score.
By CodeSafe Canada
Reading Wiring Diagrams: A Paper Lesson for Trade Students
Learn to identify drawing types, follow labelled connections, and separate reference states from question conditions using a fictional battery, switch, and lamp.
By CodeSafe Canada
Series vs Parallel Circuits: Worked 24 V Study Examples
Compare series, parallel and combination circuits using original 24 V paper examples. Follow current paths, calculate voltage drops and check your answers.
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Heat vs Temperature: Heat Transfer for Trade Students
Separate heat from temperature using original energy calculations and everyday examples of conduction, convection and radiation, with a short answer-checked self-test.
By CodeSafe Canada
Pressure vs Flow: A Guide for Gas Technician Students
Understand pressure, volumetric flow and velocity through original classroom examples. Learn what each reading can tell you and when a question needs more information.
By CodeSafe Canada
Fractions, Decimals and Ratios: A Trade Math Worksheet
Practise fractions, decimals, ratios and percentage allowances with original trade math problems, clear worked answers and simple checks for common mistakes.
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How to Read Manufacturer Manuals for Trade-School Assignments
Find the right manual, verify its model coverage and revision, and write an answer your instructor can trace. Includes a classroom evidence-note checklist.
By CodeSafe Canada
Flashcards and Active Recall for Trade Exam Prep
Build trade-study flashcards with clear prompts, checkable answers, and useful feedback. Try a flexible review schedule and fix cards that only feel familiar.
By CodeSafe Canada
How to Study for the G3 Gas Technician Exam in Ontario: 7 Study Tips
Preparing for your Ontario G3 Gas Technician exam? Use these seven practical study strategies to organize your preparation, find weak areas, improve code navigation, and make better use of practice questions.
By CodeSafe Canada
How Hard Is the G3 Gas Technician Exam in Ontario? What to Expect
Preparing for your Ontario G3 Gas Technician certification? Learn what makes G3 challenging, what you should study, common mistakes to avoid, and how to prepare more effectively.
By CodeSafe Canada
How to Become a Gas Technician in Ontario: G3,G2 & G1 Explained
Thinking about becoming a gas technician in Ontario? Learn how the G3, G2 and G1 certification levels work, what TSSA requires, and how to progress through each stage.
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Why Skilled Trades Education Is Moving Online
Discover why skilled trades students and apprentices are using online learning platforms to study technical concepts, prepare for trade exams and strengthen their job-site knowledge.
By CodeSafe Canada Education Team
Know where the lesson comes from.
These lessons are original CodeSafe learning notes. Calculation lessons link to reference material; study routines are labelled as CodeSafe methods. Each article displays its author and publication details, and a reviewer when one is recorded.
Use the method, then test it.
Work through the example, try a new set of values, and return to the concept you missed. For code-specific requirements, use the assigned reference and edition for your program.