Ontario Gas Technician 1 (G1) Certification Practice Exam 2026–2028 | Actual Advanced Practice Questions with Detailed Answers & Rationales | CSA B149.1 Code | Commercial & Industrial Gas Systems | Boiler Controls | Burner Management | Combustio

Ontario Gas Technician 1 (G1) Certification
Practice Exam 2026–2028 | Actual Advanced
Practice Questions with Detailed Answers &
Rationales | CSA B149.1 Code | Commercial
& Industrial Gas Systems | Boiler Controls |
Burner Management | Combustion Analysis |
TSSA G1 Exam Prep
Introduction
Prepare confidently for the Ontario Gas Technician 1 (G1) Certification Examination with
this comprehensive practice exam, carefully developed to reflect the knowledge and
competencies expected of Gas Technician 1 candidates working on commercial, industrial, and
institutional gas-fired equipment throughout Ontario.

Designed to reinforce both theoretical understanding and practical troubleshooting skills, this
practice exam includes realistic, exam-style multiple-choice questions with correct answers and
detailed rationales to strengthen learning and improve exam readiness.

Whether you are preparing for the TSSA G1 licensing examination, upgrading from a Gas
Technician 2 (G2) licence, or refreshing your professional knowledge, this study guide provides
broad coverage of the advanced concepts required for safe installation, commissioning,
servicing, and maintenance of gas-fired equipment.




Coverage
This comprehensive practice exam covers:

 CSA B149.1 Natural Gas and Propane Installation Code
 Ontario TSSA regulations and licensing requirements
 Gas Technician 1 (G1) scope of practice
 Commercial and industrial gas piping systems
 Gas pressure calculations and pressure drop analysis
 Pipe sizing principles
 Gas regulators and regulator venting
 Commercial gas trains and valve proving systems

, Automatic safety shutoff valves
 Burner Management Systems (BMS)
 Flame safeguard controls
 Flame rectification and ultraviolet flame detection
 Ignition systems and ignition sequencing
 Pre-purge and post-purge operation
 Pilot ignition systems
 Flame failure diagnostics
 Combustion air requirements
 Venting systems and chimney diagnostics
 Draft measurement and vent sizing
 Commercial boilers
 Industrial boilers
 Hydronic heating systems
 Steam boiler safety controls
 Rooftop units (RTUs)
 Make-Up Air Units (MAUs)
 Unit heaters
 Commercial furnaces
 Process burners
 Direct-fired equipment
 Indirect-fired heating systems
 Combustion analysis
 Carbon monoxide diagnostics
 Oxygen and carbon dioxide measurements
 Flue gas temperature analysis
 Heat exchanger inspection
 Combustion efficiency optimization
 Boiler operating sequences
 Electrical control circuits
 Control transformers
 Contactors and relays
 PLC fundamentals for combustion systems
 Safety interlocks
 Pressure switches
 Air proving switches
 High-limit controls
 Low-water cutoffs
 Temperature and pressure controls
 Lockout/Tagout (LOTO) procedures
 Leak testing procedures
 Commissioning procedures
 Preventive maintenance
 Fault isolation techniques
 Advanced troubleshooting scenarios
 Equipment documentation and commissioning records

,  Code compliance
 Professional safety practices
 Real-world G1 certification review questions with detailed explanations




Question 1

Under the Ontario Gas Technician licensing structure, which statement most accurately
describes the scope of practice for a Gas Technician 1 (G1) certificate holder?

A. The technician may service only residential gas-fired appliances below 400,000 BTU/h.

B. The technician is limited to propane appliances installed outdoors.

C. The technician is authorized to install, service, commission, and repair all classes
of gas-fired equipment within the scope permitted by Ontario regulations and
applicable codes.

D. The technician may work only under the direct supervision of a Professional Engineer.

Answer: C

Rationale: A G1 is the highest level of Ontario gas technician certification and is qualified to
work on industrial, commercial, and residential gas-fired equipment within the requirements
of the Technical Standards and Safety Authority (TSSA) and applicable legislation.




Question 2

, A commercial boiler installation must comply with the applicable installation code governing
natural gas and propane systems in Ontario. Which code is the primary installation standard
referenced for these systems?

A. Canadian Electrical Code (CSA C22.1)

B. National Building Code of Canada

C. National Fire Protection Association (NFPA 54)

D. CSA B149.1 Natural Gas and Propane Installation Code

Answer: D

Rationale: CSA B149.1 establishes installation requirements for natural gas and propane
appliances, piping, venting, combustion air, testing, and commissioning throughout Canada,
including Ontario.




Question 3

What is the primary purpose of the Technical Standards and Safety Authority (TSSA) in
Ontario with respect to fuel safety?

A. Manufacturing residential gas appliances.

B. Supplying natural gas to commercial customers.

C. Administering and enforcing fuel safety legislation, licensing requirements, and
technical safety standards.