Class B Exam Syllabus - Gas fitter Class B Certificate of Qualification


An applicant for a class B gas fitter’s certificate of qualification must meet the requirements of theSafety Standards Act, Safety Standards General RegulationandGas Safety Regulation,and must:

  • be the holder of an industry training credential in plumbing, steamfitting, refrigeration or sprinkler fitting,
  • be a trainee in a gas fitting program recognized by a provincial safety manager,
  • have held a gas utility certificate of qualification for at least 2 years, or
  • have an equivalent combination of experience and training acceptable to a provincial safety manager and have attained the standing acceptable to a provincial safety manager in a gas fitting course and examination that have been approved by a provincial safety manager.


A class B gas fitter certificate of qualification entitles the holder to perform the installation or alteration of the following gas systems under an appropriate permit:

  • an appliance with an input of 120 kW or less that displays a label or mark as follows:
    • a certification mark;
    • an approval mark issued under section 10 of the Act;
  • piping and vents.


3.1.1 Act, Regulations and Directives
  1. Apply the Safety Standards Act
  2. Apply the Safety Standards General Regulation
  3. Apply the Gas Safety Regulation
  4. Describe Safety Orders, Directives and Bulletins
3.2 GAS PROPERTIES (5% on Exam)
3.2.1 Properties of Natural Gas and Propane
  1. Apply gas laws
  2. Determine heat values
  3. List specific gravities
  4. Identify boiling points
  5. Describe the limits of flammability
  6. Describe ignition temperatures
  7. Identify flame temperatures
  8. Identify flame speeds
  9. Describe gas composition
3.3 COMBUSTION THEORY (5% on Exam)
3.3.1 Principles and Processes of Combustion
  1. Identify the products of incomplete combustion
  2. Identify the products of complete combustion
  3. Determine the BTU’s required to heat water and air
  4. Describe the requirements for combustion
  5. Determine flue gas composition and volumes
  6. Describe flue gas analysis and the equipment required
  7. Determine combustion air supply requirements such as primary, secondary, excess and dilution
3.4 REGULATORS (6% on Exam)
3.4.1 Regulator Selection and Installation
  1. Describe types of regulators such as service, line and appliance
  2. Describe the requirements for venting
  3. Size venting
  4. Identify regulator components
  5. Describe the installation of vent limiters (restrictors)
  6. Identify single-stage and two-stage propane regulators
  7. State the manufacturer, code and regulatory installation requirements for gas pressure regulators
  8. Size regulators based on manufacturer’s documentation and system requirements
3.4.2 Regulator Operation
  1. Describe the purpose and operation of gas pressure regulators found in residential, commercial and institutional installations
  2. Describe setpoint and lockup pressure
  3. Describe the effect of droop
  4. Adjust gas pressure regulators to manufacturer and system requirements
  5. Commission a line pressure regulator
3.5 PIPING THEORY (13% on Exam)
3.5.1 Install Gas Piping and Tubing Systems
  1. Identify the types of piping, tubing and hose permitted by the CSA B149.1 code
  2. Design a gas piping or tubing installation utilizing the CSA B149.1 code
  3. List the code and regulatory requirements for installing underground gas piping
  4. Describe cathodic protection and determine when it is required
  5. List the types of manual and automatic valves and their installation requirements
  6. Determine system pressures and maximum allowable pressure drops
  7. Size piping systems for propane and natural gas
  8. List the requirements when connecting piping and tubing to the gas utilities meter set
  9. Determine piping and tubing support requirements
  10. Install drip and dirt pockets
  11. Describe the types propane storage systems used to supply gas to residential and commercial appliances
  12. Describe propane cylinder/tank equipment and valves
  13. Describe propane cylinder markings and requalification requirements
  14. Describe the information contained on propane tank data plates
3.5.2 Testing and Commissioning
  1. Inspect fuel delivery components
  2. Determine testing requirements including pressure and duration
  3. Select testing equipment
  4. List the procedures to commission piping and tubing systems
  5. Identify the purging procedures for pipe under 4 inch diameter
  6. Describe the purging requirements for piping larger than 4 inch in diameter
  7. List the process to purge and re-gasify the system
  8. Measure and record inlet and outlet pressures to ensure they are within manufacturers’ specifications and code
  9. Check for leaks using electronic leak detectors and leak detection solutions
3.6.1 Combustion Air Supply Sizing
  1. Determine air supply requirements for residential installations
  2. Determine air supply requirements for commercial and institutional facilities
  3. Size air supply ducting for natural draft and fan-assisted combustion systems
  4. Size air supply ducting for fan-assisted and power burners
  5. Size louvers and grills
3.6.2 Air Supply System Installation
  1. Describe the installation requirements for air supply systems according to the CSA B149.1 code
  2. Describe high and low volume installations
  3. Describe the code and regulatory requirements for installing air supply systems
  4. Install grills and louvers
  5. Describe the installation considerations for mechanical air supply systems
3.7 VENTING THEORY (14% on Exam)
3.7.1 Select and Install Venting Systems
  1. List the types and classification of venting material permitted for gas-fired appliances
  2. Select venting material based on appliance type and installation requirements
  3. Describe appliance categories based on efficiency and vent pressure
  4. Describe venting material temperature limitations
  5. Describe the procedure for sizing category ll, lll and lV venting systems
  6. Size category l venting systems
  7. Describe the code and regulatory requirements for vent terminations
  8. Install venting systems based on code and regulatory requirements
  9. Determine clearances to combustible materials
3.7.2 Venting System Operation
  1. Describe the building as a system
  2. Determine net stack temperature
  3. Describe vent pressure
  4. Describe the operation of a direct vent appliance
  5. Describe the operation of a natural draft appliance
  6. Describe the operation of a fan-assisted combustion appliance
3.7.3 Select and Install Draft Controls
  1. Describe draft hoods and diverters and their purpose
  2. Describe single-acting and double-acting barometric dampers
  3. Identify vent and flue dampers
  4. Describe power ventors
  5. Select draft controls based on manufacturer and regulatory requirements
  6. Apply the CSA B149.1 code to the installation of draft control devices
  7. Test and commission draft controls
3.8.1 Gas Meters
  1. List gas meter types
  2. Describe the operation of positive-displacement gas meters
  3. Describe the purpose of a test dial
3.8.2 Clocking
  1. Calculate appliance input based on gas meter readings
  2. Apply pressure correction factors
  3. Determine if the appliance input is within manufacturer and regulatory requirements
  4. Determine appliance input ratings when installed above sea level
3.9 BURNER OPERATION (5% on Exam)
3.9.1 Burner Orifices
  1. List how burner orifices are sized
  2. Describe orifice sizing methods
  3. Describe the orifice flow formula
  4. Describe the effect that altitude has on orifice sizing
  5. Determine burner orifice size based on CSA B149.1 tables
  6. Convert burners to operate on propane or natural gas
3.9.2 Burner components and operation
  1. Identify the parts of an atmospheric burner
  2. Describe burner air supply such as primary and secondary
  3. Describe the operation on an atmospheric burner
  4. Identify burner types
  5. Describe port loading
3.10 ELECTRICAL (12% on Exam)
3.10.1 Canadian Electrical Code (CEC) and Regulations
  1. Apply CEC sections 0, 2, 4, 6, 8, 10, 12, 14, 16, 26 and 28
  2. Size and install bonding conductors
  3. Describe nonmetallic and metallic sheathed cable
  4. Select, size and install power supply conductors for gas appliances and motors
  5. Describe Class 2 circuits
  6. Install combustion safety control circuits
  7. Describe the electrical work that may be performed by a Class B gas fitter
  8. Describe when electrical permits are required
3.10.2 Electrical Equipment
  1. Identify electrical symbols
  2. Apply principles of electricity
  3. Describe the types of switches found on appliances with a maximum input of 120 kW including limits and interlocks
  4. Describe the types of transformers encountered with gas appliances
  5. Select transformers based on primary and secondary voltages, as well as VA ratings
  6. Describe when a 120/24 volt transformer must be wired in phase and the anticipated readings
  7. Explain relays and their operation
  8. Select and install relays
  9. Use meters to determine voltage, current and resistance of electrical circuits
  10. Describe flame rectification and flame current
  11. Apply Ohm’s Law
  12. Calculate power, voltage, current and resistance in series and parallel circuits
  13. Analyze heating circuits for appliances with inputs that do not exceed 120 kW
3.11.1 Appliance Installation
  1. Ensure appliance installation meets manufacturer, code and regulatory requirements
  2. List the requirements when installing appliances in residential buildings
  3. List the considerations when installing appliances in multi-family dwellings
  4. List the requirements that must be considered when installing gas-fired appliances in vehicle storage and repair facilities
  5. List the requirements when installing appliances in commercial kitchens
  6. Identify appliance certification and approvals
3.11.2 Appliance Components
  1. Describe low pressure boilers and their ancillary equipment
  2. Describe water-tube and fire-tube boilers
  3. Describe the application for mixing valves
  4. Describe multi-boiler hydronic heating system components.
  5. List the components encountered on residential and commercial cooking equipment
  6. Identify the components of a condensing forced air furnace
3.11.3 Control Narratives
  1. Determine sequence of operation of an appliance based on wiring diagrams and schematics
  2. Describe the operation of domestic water heaters including storage and tankless
  3. Describe the operation of low pressure boilers
  4. Describe the operation of residential forced air furnaces
  5. Describe the operation of a gas fireplace
3.11.4 Commissioning
  1. List the factors to consider when starting up a system
  2. Determine the commissioning requirements for gas fired appliances
  3. Explain the operation of gas valve trains for appliances rated at 120 kW or less
  4. Perform the inspection of fuel train system such as; visual, electrical parameters, tightness of closure, regulator lockup and manifold pressure
  5. Ensure temperature rise through the appliance is within acceptable limits
  6. Check External Static Pressure (ESP) is within acceptable
  7. Set fan speeds
  8. Balance hydronic heating and forced air space heating systems
  9. Check vent pressures and draft
  10. Determine supply water temperatures for residential hydronic heating systems
  11. Inspect burner performance using a combustion test analyzer to verify air gas mix, combustion air volume, CO levels and stack temperature
3.12 OPERATING CONTROLS (10% on Exam)
3.12.1 Controls and Limits
  1. Describe the installation and adjustment of operating controls found on residential appliances including furnaces, boilers, domestic water heaters, cooking equipment and fireplaces
  2. Identify types of operating controls
  3. Select operating controls
  4. Describe the installation and operation of outdoor reset controls
  5. Describe and identify types of safety limits
  6. Select safety limits
  7. List types of gas valves and their operating characteristics
  8. Describe and select ignition systems for appliances with a maximum input of 120 kW
  9. Describe and select flame safeguards for appliances with a maximum input of 120 kW
3.12.2 Testing
  1. Adjust operating controls to system requirements
  2. Test safety limits such as high limit, high and low water cut-offs, flow switches and high and low gas pressure switches to verify operation
  3. Perform pilot turndown test to confirm smooth lighting of burners
  4. Test flame safeguards to ensure that they meet manufacturer and regulatory requirements
3.13.1 Service
  1. Describe sequence of operation to assist with troubleshooting
  2. List common electrical faults
  3. Interpret electrical readings
  4. Troubleshoot residential heating system electrical circuits
  5. Inspect venting, chimneys and air supply
  6. Inspect mechanical components such as switches, valves, dampers, fans, motors and air differential proving switches
  7. Troubleshoot burner operation
  8. Troubleshoot systems utilizing wiring diagrams and schematics
  9. List the procedures for repairing a regulator such as; isolation, replacing components and confirming operation
  10. Service a regulator that is damaged or is not meeting system performance requirements
  11. Describe appliance efficiency including combustion, AFUE and thermal efficiency
  12. Determine appliance efficiency
  13. Determine the results of faulty limits and controls
  14. Identify the signs when immediate service is required
  15. List items to consider when making a repair, such as; isolation, removing faulty components and returning to service
  16. Monitor equipment performance to identify faults or erratic operation
  17. Select and use diagnostic tools such as manometers, draft gauges, combustion analyzers, multimeters and ammeters
  18. Verify replacement parts meet manufacturer’s requirements and operate according to specifications
  19. Lock-out and tag-out system by isolating energy sources
  20. Remove and reassemble protective covers, shields and other components to access repair area
  21. Check for leaks to ensure that systems are safe
3.13.2 Maintenance
  1. Describe the maintenance of gas-fired appliances with a maximum input of 120 kW
  2. Perform the annual service requirements for residential forced air furnaces
  3. Perform the annual service requirements for residential boilers
  4. Perform the annual service requirements for domestic water heaters
  5. Perform gas fireplace cleaning and servicing
  6. Replace components such as belts, flame rods, filters and gaskets according to maintenance schedule
  7. Document repairs