ONTARIO GAS TECHNICIAN 2 (G2) CERTIFICATION EXAM – QUESTIONS AND ANSWERS |
VERIFIED AND WELL DETAILED ANSWERS | PLUS RATIONALES | GUARANTEED PASS | LATEST
EXAM UPDATE | EXAM PREP | STUDY GUIDE | PRACTICE TEST
1. A gas technician is preparing to install a residential natural gas appliance. Before beginning
the installation, which action is the most important first step?
A. Confirm the appliance colour matches the customer’s preference
B. Verify the appliance specifications, installation instructions, and site requirements
C. Begin connecting the gas piping to save time
D. Adjust the appliance controls before positioning it
════════════════════
Correct Answer: B. Verify the appliance specifications, installation instructions, and site
requirements
Rationale:
The installation manual and appliance specifications provide essential requirements for
clearances, venting, gas supply, and installation procedures. Reviewing these prevents unsafe
installation practices. The other options focus on appearance or premature work before safety
requirements are confirmed.
════════════════════
2. A G2 technician measures the gas pressure at an appliance inlet and finds it is below the
manufacturer’s specified operating range. What should the technician do next?
A. Increase the appliance manifold pressure adjustment immediately
B. Replace the appliance gas valve
C. Investigate the gas supply system to determine the cause of low pressure
D. Continue operation because the appliance will self-adjust
════════════════════
Correct Answer: C. Investigate the gas supply system to determine the cause of low
pressure
Rationale:
Low inlet pressure may result from supply restrictions, improper piping, regulator issues, or
other system problems. Adjusting appliance components without identifying the cause can
create unsafe conditions.
,════════════════════
3. Which component of a gas appliance is primarily responsible for preventing combustion
products from entering the occupied space?
A. Venting system
B. Thermostat
C. Gas shut-off valve
D. Ignition module
════════════════════
Correct Answer: A. Venting system
Rationale:
The venting system safely removes combustion products from the appliance to the outdoors.
Thermostats, valves, and ignition systems control operation but do not perform exhaust
removal.
════════════════════
4. During a service call, a customer reports smelling gas near a furnace. What is the
technician’s first responsibility?
A. Immediately relight the pilot
B. Shut off the gas supply if safe and follow gas leak procedures
C. Increase ventilation by opening the furnace cabinet
D. Test the thermostat operation
════════════════════
Correct Answer: B. Shut off the gas supply if safe and follow gas leak procedures
Rationale:
A suspected gas leak requires immediate attention to eliminate risk. The technician must
follow established safety procedures before performing troubleshooting or repairs.
════════════════════
5. What is the purpose of a flame sensor in a modern gas-fired appliance?
A. To increase burner temperature
B. To measure incoming gas pressure
,C. To confirm flame presence and allow safe continued operation
D. To regulate room temperature
════════════════════
Correct Answer: C. To confirm flame presence and allow safe continued operation
Rationale:
The flame sensor proves that ignition has occurred. If flame is not detected, the control system
shuts down gas flow to prevent unburned gas accumulation.
════════════════════
6. A technician notices that a burner flame is mostly yellow instead of steady blue. What does
this condition most likely indicate?
A. Proper combustion under all conditions
B. Possible incomplete combustion requiring investigation
C. Excessive thermostat calibration
D. Correct manifold pressure adjustment
════════════════════
Correct Answer: B. Possible incomplete combustion requiring investigation
Rationale:
A yellow flame can indicate incomplete combustion, insufficient air supply, or burner
problems. Combustion conditions must be checked before returning the appliance to service.
════════════════════
7. Which document should a G2 technician consult for appliance-specific installation
requirements?
A. Customer invoice
B. Manufacturer’s installation instructions
C. Sales brochure
D. Previous service receipt only
════════════════════
Correct Answer: B. Manufacturer’s installation instructions
Rationale:
, Manufacturer instructions contain required installation details such as clearances, venting,
electrical requirements, and approved configurations.
════════════════════
8. A technician is testing for gas leakage after completing a piping connection. Which method
is acceptable?
A. Using an open flame near the connection
B. Smelling the fitting area only
C. Using an approved leak detection method
D. Ignoring the connection if the appliance operates
════════════════════
Correct Answer: C. Using an approved leak detection method
Rationale:
Approved leak detection methods identify unsafe gas leakage without creating an ignition
hazard. Open flames are prohibited for leak testing.
════════════════════
9. What is the primary purpose of a gas appliance rating plate?
A. To provide decorative information
B. To identify appliance requirements and certification details
C. To replace the installation manual
D. To indicate customer maintenance preferences
════════════════════
Correct Answer: B. To identify appliance requirements and certification details
Rationale:
The rating plate provides important information including input rating, fuel type, model data,
and certification requirements needed for proper installation and servicing.
════════════════════
10. A technician arrives at a home where a customer has modified a gas appliance without
approval. What is the most appropriate professional response?
A. Ignore the modification if the appliance is running
VERIFIED AND WELL DETAILED ANSWERS | PLUS RATIONALES | GUARANTEED PASS | LATEST
EXAM UPDATE | EXAM PREP | STUDY GUIDE | PRACTICE TEST
1. A gas technician is preparing to install a residential natural gas appliance. Before beginning
the installation, which action is the most important first step?
A. Confirm the appliance colour matches the customer’s preference
B. Verify the appliance specifications, installation instructions, and site requirements
C. Begin connecting the gas piping to save time
D. Adjust the appliance controls before positioning it
════════════════════
Correct Answer: B. Verify the appliance specifications, installation instructions, and site
requirements
Rationale:
The installation manual and appliance specifications provide essential requirements for
clearances, venting, gas supply, and installation procedures. Reviewing these prevents unsafe
installation practices. The other options focus on appearance or premature work before safety
requirements are confirmed.
════════════════════
2. A G2 technician measures the gas pressure at an appliance inlet and finds it is below the
manufacturer’s specified operating range. What should the technician do next?
A. Increase the appliance manifold pressure adjustment immediately
B. Replace the appliance gas valve
C. Investigate the gas supply system to determine the cause of low pressure
D. Continue operation because the appliance will self-adjust
════════════════════
Correct Answer: C. Investigate the gas supply system to determine the cause of low
pressure
Rationale:
Low inlet pressure may result from supply restrictions, improper piping, regulator issues, or
other system problems. Adjusting appliance components without identifying the cause can
create unsafe conditions.
,════════════════════
3. Which component of a gas appliance is primarily responsible for preventing combustion
products from entering the occupied space?
A. Venting system
B. Thermostat
C. Gas shut-off valve
D. Ignition module
════════════════════
Correct Answer: A. Venting system
Rationale:
The venting system safely removes combustion products from the appliance to the outdoors.
Thermostats, valves, and ignition systems control operation but do not perform exhaust
removal.
════════════════════
4. During a service call, a customer reports smelling gas near a furnace. What is the
technician’s first responsibility?
A. Immediately relight the pilot
B. Shut off the gas supply if safe and follow gas leak procedures
C. Increase ventilation by opening the furnace cabinet
D. Test the thermostat operation
════════════════════
Correct Answer: B. Shut off the gas supply if safe and follow gas leak procedures
Rationale:
A suspected gas leak requires immediate attention to eliminate risk. The technician must
follow established safety procedures before performing troubleshooting or repairs.
════════════════════
5. What is the purpose of a flame sensor in a modern gas-fired appliance?
A. To increase burner temperature
B. To measure incoming gas pressure
,C. To confirm flame presence and allow safe continued operation
D. To regulate room temperature
════════════════════
Correct Answer: C. To confirm flame presence and allow safe continued operation
Rationale:
The flame sensor proves that ignition has occurred. If flame is not detected, the control system
shuts down gas flow to prevent unburned gas accumulation.
════════════════════
6. A technician notices that a burner flame is mostly yellow instead of steady blue. What does
this condition most likely indicate?
A. Proper combustion under all conditions
B. Possible incomplete combustion requiring investigation
C. Excessive thermostat calibration
D. Correct manifold pressure adjustment
════════════════════
Correct Answer: B. Possible incomplete combustion requiring investigation
Rationale:
A yellow flame can indicate incomplete combustion, insufficient air supply, or burner
problems. Combustion conditions must be checked before returning the appliance to service.
════════════════════
7. Which document should a G2 technician consult for appliance-specific installation
requirements?
A. Customer invoice
B. Manufacturer’s installation instructions
C. Sales brochure
D. Previous service receipt only
════════════════════
Correct Answer: B. Manufacturer’s installation instructions
Rationale:
, Manufacturer instructions contain required installation details such as clearances, venting,
electrical requirements, and approved configurations.
════════════════════
8. A technician is testing for gas leakage after completing a piping connection. Which method
is acceptable?
A. Using an open flame near the connection
B. Smelling the fitting area only
C. Using an approved leak detection method
D. Ignoring the connection if the appliance operates
════════════════════
Correct Answer: C. Using an approved leak detection method
Rationale:
Approved leak detection methods identify unsafe gas leakage without creating an ignition
hazard. Open flames are prohibited for leak testing.
════════════════════
9. What is the primary purpose of a gas appliance rating plate?
A. To provide decorative information
B. To identify appliance requirements and certification details
C. To replace the installation manual
D. To indicate customer maintenance preferences
════════════════════
Correct Answer: B. To identify appliance requirements and certification details
Rationale:
The rating plate provides important information including input rating, fuel type, model data,
and certification requirements needed for proper installation and servicing.
════════════════════
10. A technician arrives at a home where a customer has modified a gas appliance without
approval. What is the most appropriate professional response?
A. Ignore the modification if the appliance is running
