Ontario Gas Technician 2 (G2) Certification
Exam With Actual Questions & Verified
Answers, Plus Explained Rationales/Expert
Verified For Guaranteed 100% Pass
2026/Latest Update/Instant Download Pdf
1. What is the primary purpose of a gas regulator?
A. Increase gas pressure
B. Store gas
C. Reduce and control gas pressure
D. Measure gas volume
Rationale: Gas regulators are designed to reduce high inlet gas
pressure to a safe, usable outlet pressure and maintain
consistent flow despite demand changes.
2. Which instrument is used to measure gas pressure?
A. Thermometer
B. Barometer
C. Manometer
D. Hygrometer
Rationale: A manometer measures pressure differences and is
commonly used in gas systems to verify proper operation.
3. What is the main component responsible for ignition in a modern
gas furnace?
A. Thermocouple
B. Transformer
C. Igniter (hot surface or spark)
D. Limit switch
, Rationale: Modern furnaces use electronic ignition systems such
as hot surface igniters or spark igniters instead of pilot lights.
4. What does BTU stand for?
A. Basic Thermal Unit
B. British Temperature Unit
C. British Thermal Unit
D. Burner Thermal Unit
Rationale: A BTU is a unit of heat energy representing the
amount needed to raise the temperature of one pound of water
by one degree Fahrenheit.
5. What is the function of a thermocouple?
A. Control gas pressure
B. Sense flame and shut off gas if flame is lost
C. Ignite gas
D. Measure airflow
Rationale: A thermocouple generates a small voltage when
heated by a flame, allowing gas flow; if the flame goes out, gas
supply is shut off.
6. What type of gas is lighter than air?
A. Propane
B. Butane
C. Natural gas
D. Carbon dioxide
Rationale: Natural gas rises because it is lighter than air, while
propane is heavier and settles low.
7. What is the purpose of a draft hood?
A. Increase combustion efficiency
B. Reduce gas pressure
C. Stabilize draft and prevent backdrafting
, D. Filter air
Rationale: A draft hood ensures proper venting and protects
burners from draft fluctuations.
8. Which component controls the temperature in a gas appliance?
A. Valve
B. Transformer
C. Thermostat
D. Orifice
Rationale: A thermostat regulates temperature by signaling the
appliance to turn on or off.
9. What is the main hazard of incomplete combustion?
A. Oxygen production
B. Heat loss
C. Carbon monoxide formation
D. Water vapor
Rationale: Incomplete combustion produces carbon monoxide, a
toxic and potentially fatal gas.
10. What is the purpose of a pressure switch in a furnace?
A. Measure gas flow
B. Ignite gas
C. Ensure proper venting/airflow before ignition
D. Control temperature
Rationale: The pressure switch confirms that the inducer fan is
creating proper draft before allowing ignition.
11. What tool is used to detect gas leaks?
A. Voltmeter
B. Thermometer
C. Gas detector or soap solution
D. Ammeter
Exam With Actual Questions & Verified
Answers, Plus Explained Rationales/Expert
Verified For Guaranteed 100% Pass
2026/Latest Update/Instant Download Pdf
1. What is the primary purpose of a gas regulator?
A. Increase gas pressure
B. Store gas
C. Reduce and control gas pressure
D. Measure gas volume
Rationale: Gas regulators are designed to reduce high inlet gas
pressure to a safe, usable outlet pressure and maintain
consistent flow despite demand changes.
2. Which instrument is used to measure gas pressure?
A. Thermometer
B. Barometer
C. Manometer
D. Hygrometer
Rationale: A manometer measures pressure differences and is
commonly used in gas systems to verify proper operation.
3. What is the main component responsible for ignition in a modern
gas furnace?
A. Thermocouple
B. Transformer
C. Igniter (hot surface or spark)
D. Limit switch
, Rationale: Modern furnaces use electronic ignition systems such
as hot surface igniters or spark igniters instead of pilot lights.
4. What does BTU stand for?
A. Basic Thermal Unit
B. British Temperature Unit
C. British Thermal Unit
D. Burner Thermal Unit
Rationale: A BTU is a unit of heat energy representing the
amount needed to raise the temperature of one pound of water
by one degree Fahrenheit.
5. What is the function of a thermocouple?
A. Control gas pressure
B. Sense flame and shut off gas if flame is lost
C. Ignite gas
D. Measure airflow
Rationale: A thermocouple generates a small voltage when
heated by a flame, allowing gas flow; if the flame goes out, gas
supply is shut off.
6. What type of gas is lighter than air?
A. Propane
B. Butane
C. Natural gas
D. Carbon dioxide
Rationale: Natural gas rises because it is lighter than air, while
propane is heavier and settles low.
7. What is the purpose of a draft hood?
A. Increase combustion efficiency
B. Reduce gas pressure
C. Stabilize draft and prevent backdrafting
, D. Filter air
Rationale: A draft hood ensures proper venting and protects
burners from draft fluctuations.
8. Which component controls the temperature in a gas appliance?
A. Valve
B. Transformer
C. Thermostat
D. Orifice
Rationale: A thermostat regulates temperature by signaling the
appliance to turn on or off.
9. What is the main hazard of incomplete combustion?
A. Oxygen production
B. Heat loss
C. Carbon monoxide formation
D. Water vapor
Rationale: Incomplete combustion produces carbon monoxide, a
toxic and potentially fatal gas.
10. What is the purpose of a pressure switch in a furnace?
A. Measure gas flow
B. Ignite gas
C. Ensure proper venting/airflow before ignition
D. Control temperature
Rationale: The pressure switch confirms that the inducer fan is
creating proper draft before allowing ignition.
11. What tool is used to detect gas leaks?
A. Voltmeter
B. Thermometer
C. Gas detector or soap solution
D. Ammeter
