MASSACHUSETTS GASFITER MASTER EXAM
QUESTIONS AND CORRECT ANSWERS (VERIFIED
ANSWERS) Q&A 2026 |INSTANT DOWNLOAD PDF
1. What is the maximum allowable pressure for a residential
natural gas system in Massachusetts?
A. 0.5 psi
B. 2 psi
C. 5 psi
D. 10 psi
Rationale: Residential natural gas systems are low-pressure
systems to ensure safety. Higher pressures require commercial-
grade piping and regulators.
Correct Answer: A. 0.5 psi
2. Which type of venting is typically required for a high-
efficiency condensing gas furnace?
A. Aluminum Type B vent
B. Single-wall black steel vent
C. PVC or CPVC vent
D. Galvanized steel vent
,Rationale: High-efficiency condensing furnaces produce cool,
acidic flue gases that can corrode metal vents, so corrosion-
resistant plastic venting is required.
Correct Answer: C. PVC or CPVC vent
3. What is the purpose of a gas regulator in a natural gas
system?
A. To increase the gas pressure to appliances
B. To maintain a constant outlet pressure regardless of inlet
variations
C. To measure gas usage
D. To detect gas leaks
Rationale: Gas regulators reduce and stabilize the incoming
pressure so appliances receive a safe, consistent gas flow.
Correct Answer: B. To maintain a constant outlet pressure
regardless of inlet variations
4. Which tool is required to test gas piping for leaks according
to Massachusetts code?
A. Soap solution or approved gas detector
B. Water immersion
C. Magnetic field detector
D. Thermometer
,Rationale: Leak testing requires methods that safely detect
escaping gas without introducing ignition sources.
Correct Answer: A. Soap solution or approved gas detector
5. What is the minimum distance a gas meter must be
installed from an ignition source?
A. 6 inches
B. 12 inches
C. 5 feet
D. 10 feet
Rationale: To prevent accidental ignition of leaked gas, meters
must be located at a safe distance from potential ignition
sources.
Correct Answer: C. 5 feet
6. When sizing a gas pipe, what factor must be considered to
ensure proper appliance operation?
A. Pipe color
B. Pipe length, pressure drop, and BTU demand
C. Pipe age
D. Pipe manufacturer
Rationale: Correct pipe sizing depends on total appliance load,
distance from supply, and pressure drop. Improper sizing can
cause appliance malfunction.
, Correct Answer: B. Pipe length, pressure drop, and BTU demand
7. Which gas appliance requires a vent that rises vertically at
least 12 inches before any elbow?
A. Tankless water heater
B. Atmospheric gas furnace
C. Direct vent fireplace
D. Gas stove
Rationale: Certain venting configurations require an initial
vertical rise to ensure proper draft and prevent backflow of
combustion gases.
Correct Answer: B. Atmospheric gas furnace
8. What is the primary safety device installed on gas water
heaters to prevent excessive pressure buildup?
A. Thermostat
B. Temperature and Pressure Relief Valve (T&P valve)
C. Gas regulator
D. Draft hood
Rationale: The T&P valve opens if the temperature or pressure
exceeds safe limits, preventing potential explosions.
Correct Answer: B. Temperature and Pressure Relief Valve (T&P
valve)
QUESTIONS AND CORRECT ANSWERS (VERIFIED
ANSWERS) Q&A 2026 |INSTANT DOWNLOAD PDF
1. What is the maximum allowable pressure for a residential
natural gas system in Massachusetts?
A. 0.5 psi
B. 2 psi
C. 5 psi
D. 10 psi
Rationale: Residential natural gas systems are low-pressure
systems to ensure safety. Higher pressures require commercial-
grade piping and regulators.
Correct Answer: A. 0.5 psi
2. Which type of venting is typically required for a high-
efficiency condensing gas furnace?
A. Aluminum Type B vent
B. Single-wall black steel vent
C. PVC or CPVC vent
D. Galvanized steel vent
,Rationale: High-efficiency condensing furnaces produce cool,
acidic flue gases that can corrode metal vents, so corrosion-
resistant plastic venting is required.
Correct Answer: C. PVC or CPVC vent
3. What is the purpose of a gas regulator in a natural gas
system?
A. To increase the gas pressure to appliances
B. To maintain a constant outlet pressure regardless of inlet
variations
C. To measure gas usage
D. To detect gas leaks
Rationale: Gas regulators reduce and stabilize the incoming
pressure so appliances receive a safe, consistent gas flow.
Correct Answer: B. To maintain a constant outlet pressure
regardless of inlet variations
4. Which tool is required to test gas piping for leaks according
to Massachusetts code?
A. Soap solution or approved gas detector
B. Water immersion
C. Magnetic field detector
D. Thermometer
,Rationale: Leak testing requires methods that safely detect
escaping gas without introducing ignition sources.
Correct Answer: A. Soap solution or approved gas detector
5. What is the minimum distance a gas meter must be
installed from an ignition source?
A. 6 inches
B. 12 inches
C. 5 feet
D. 10 feet
Rationale: To prevent accidental ignition of leaked gas, meters
must be located at a safe distance from potential ignition
sources.
Correct Answer: C. 5 feet
6. When sizing a gas pipe, what factor must be considered to
ensure proper appliance operation?
A. Pipe color
B. Pipe length, pressure drop, and BTU demand
C. Pipe age
D. Pipe manufacturer
Rationale: Correct pipe sizing depends on total appliance load,
distance from supply, and pressure drop. Improper sizing can
cause appliance malfunction.
, Correct Answer: B. Pipe length, pressure drop, and BTU demand
7. Which gas appliance requires a vent that rises vertically at
least 12 inches before any elbow?
A. Tankless water heater
B. Atmospheric gas furnace
C. Direct vent fireplace
D. Gas stove
Rationale: Certain venting configurations require an initial
vertical rise to ensure proper draft and prevent backflow of
combustion gases.
Correct Answer: B. Atmospheric gas furnace
8. What is the primary safety device installed on gas water
heaters to prevent excessive pressure buildup?
A. Thermostat
B. Temperature and Pressure Relief Valve (T&P valve)
C. Gas regulator
D. Draft hood
Rationale: The T&P valve opens if the temperature or pressure
exceeds safe limits, preventing potential explosions.
Correct Answer: B. Temperature and Pressure Relief Valve (T&P
valve)
