Nevada Gas Appliance Service
Technician Certification Exam Practice
Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. What is the primary purpose of a gas pressure regulator in a natural
gas appliance system?
A. To increase gas pressure
B. To filter impurities in gas
C. To maintain a consistent gas pressure to the appliance
D. To convert natural gas to propane
A gas pressure regulator ensures appliances receive a steady, safe
gas pressure regardless of fluctuations in supply lines.
2. Which of the following is the correct method for testing for gas leaks
in a pipe joint?
A. Using a naked flame
B. Using a wire brush
C. Using a soap and water solution
D. Using compressed air alone
Soap and water solution creates bubbles at leak points, allowing safe
detection without risk of ignition.
3. What is the minimum clearance required between a gas water heater
and combustible materials?
A. 1 inch
B. 6 inches
C. 12 inches
D. 24 inches
, Building codes and appliance manuals typically require a minimum of
12 inches for safety and maintenance access.
4. What is the main function of a thermocouple in a gas appliance?
A. To increase gas flow
B. To ignite the burner
C. To detect pilot flame and allow gas valve operation
D. To regulate temperature
The thermocouple senses the pilot flame; if the flame goes out, it
signals the gas valve to close for safety.
5. Which type of gas is heavier than air and can accumulate at floor level
if leaked?
A. Methane
B. Propane
C. Natural gas
D. Hydrogen
Propane is heavier than air and can settle in low areas, posing a fire
and explosion hazard.
6. What is the typical ignition source in a standing pilot gas appliance?
A. Spark plug
B. Pilot flame
C. Battery ignition
D. Electric igniter
A standing pilot flame continuously ignites the main burner when the
appliance calls for heat.
7. Which material is commonly used for gas supply lines inside a
building?
A. PVC
B. Black steel pipe
C. Aluminum
D. Copper tubing without approved coating
Black steel pipe is durable, approved for natural gas and propane,
and resistant to pressure and temperature variations.
8. What is the correct action if a gas appliance emits a strong odor of
gas?
A. Turn on all electrical switches
, B. Attempt to light the appliance immediately
C. Evacuate the area and call the gas utility
D. Use a fan to ventilate and continue operation
Gas leaks are extremely dangerous; immediate evacuation and
notifying professionals is essential.
9. What is the purpose of the venting system in a gas appliance?
A. To increase gas pressure
B. To provide electrical grounding
C. To remove combustion byproducts safely outdoors
D. To filter the incoming gas
Proper venting prevents buildup of carbon monoxide and other
harmful combustion gases inside the building.
10. What is the proper way to solder a copper gas line joint?
A. Apply heat without cleaning
B. Use any type of flux
C. Clean, apply approved flux, and heat evenly until solder flows
D. Apply solder directly to cold joint
Cleaning and using proper flux ensures a tight, leak-free joint;
heating must be controlled to avoid hazards.
11. Which device prevents gas from flowing if the pilot flame goes
out?
A. Pressure regulator
B. Gas meter
C. Thermopile or thermocouple
D. Expansion valve
Thermocouples or thermopiles act as safety devices by shutting off
the gas supply if the pilot flame extinguishes.
12. Which safety standard applies to gas appliance installation in
Nevada?
A. ANSI Z21 series
B. NFPA 54 (National Fuel Gas Code)
C. OSHA 1910
D. IEC 60335
NFPA 54 governs installation, maintenance, and safety requirements
for fuel gas systems in the U.S., including Nevada.
Technician Certification Exam Practice
Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. What is the primary purpose of a gas pressure regulator in a natural
gas appliance system?
A. To increase gas pressure
B. To filter impurities in gas
C. To maintain a consistent gas pressure to the appliance
D. To convert natural gas to propane
A gas pressure regulator ensures appliances receive a steady, safe
gas pressure regardless of fluctuations in supply lines.
2. Which of the following is the correct method for testing for gas leaks
in a pipe joint?
A. Using a naked flame
B. Using a wire brush
C. Using a soap and water solution
D. Using compressed air alone
Soap and water solution creates bubbles at leak points, allowing safe
detection without risk of ignition.
3. What is the minimum clearance required between a gas water heater
and combustible materials?
A. 1 inch
B. 6 inches
C. 12 inches
D. 24 inches
, Building codes and appliance manuals typically require a minimum of
12 inches for safety and maintenance access.
4. What is the main function of a thermocouple in a gas appliance?
A. To increase gas flow
B. To ignite the burner
C. To detect pilot flame and allow gas valve operation
D. To regulate temperature
The thermocouple senses the pilot flame; if the flame goes out, it
signals the gas valve to close for safety.
5. Which type of gas is heavier than air and can accumulate at floor level
if leaked?
A. Methane
B. Propane
C. Natural gas
D. Hydrogen
Propane is heavier than air and can settle in low areas, posing a fire
and explosion hazard.
6. What is the typical ignition source in a standing pilot gas appliance?
A. Spark plug
B. Pilot flame
C. Battery ignition
D. Electric igniter
A standing pilot flame continuously ignites the main burner when the
appliance calls for heat.
7. Which material is commonly used for gas supply lines inside a
building?
A. PVC
B. Black steel pipe
C. Aluminum
D. Copper tubing without approved coating
Black steel pipe is durable, approved for natural gas and propane,
and resistant to pressure and temperature variations.
8. What is the correct action if a gas appliance emits a strong odor of
gas?
A. Turn on all electrical switches
, B. Attempt to light the appliance immediately
C. Evacuate the area and call the gas utility
D. Use a fan to ventilate and continue operation
Gas leaks are extremely dangerous; immediate evacuation and
notifying professionals is essential.
9. What is the purpose of the venting system in a gas appliance?
A. To increase gas pressure
B. To provide electrical grounding
C. To remove combustion byproducts safely outdoors
D. To filter the incoming gas
Proper venting prevents buildup of carbon monoxide and other
harmful combustion gases inside the building.
10. What is the proper way to solder a copper gas line joint?
A. Apply heat without cleaning
B. Use any type of flux
C. Clean, apply approved flux, and heat evenly until solder flows
D. Apply solder directly to cold joint
Cleaning and using proper flux ensures a tight, leak-free joint;
heating must be controlled to avoid hazards.
11. Which device prevents gas from flowing if the pilot flame goes
out?
A. Pressure regulator
B. Gas meter
C. Thermopile or thermocouple
D. Expansion valve
Thermocouples or thermopiles act as safety devices by shutting off
the gas supply if the pilot flame extinguishes.
12. Which safety standard applies to gas appliance installation in
Nevada?
A. ANSI Z21 series
B. NFPA 54 (National Fuel Gas Code)
C. OSHA 1910
D. IEC 60335
NFPA 54 governs installation, maintenance, and safety requirements
for fuel gas systems in the U.S., including Nevada.
