RMGA Exam Questions with Correct Answers Latest Version 2025 Graded A+
How heavy is gasoline vapor? - Answers 2-4 times weight of air
What is the most harmful byproduct of combustion? - Answers Carbon Monoxide
What is the ignition temperature of natural gas? - Answers 1100-1200 degrees Farenheit
What is the density of propane vapor? - Answers 1.56
What are the byproducts of combustion? - Answers CO2, Water Vapor, Heat
What is the ratio for complete combustion of natural gas? - Answers 1 part natural gas to 10 part air
What is the maximum length of a flexible gas connector going to a furnace? - Answers 6 feet
What are the materials that can be used for piping natural gas? (4) - Answers Iron/steel, galvanize/black,
CSST, Polyethylene
What is an anode used for? - Answers To provide cathodic protection
What type of gas appliance is not require to have a shut off valve located in the same room? - Answers
Decorative appliance and room heaters
How close should a shut off valve be located to an appliance? - Answers Within 6 feet of the appliance
and in the same room
What is the minimum pipe size to a furnace and water heater location requested by Dominion? -
Answers 1"
What is the maximum pressure allowed before the use of welded joints is required? - Answers 5 PSIG
When is a tracer wire used? - Answers For underground non-metallic (plastic) gas lines
What methods can be used to join plastic gas pipe? - Answers Approved mechanical fittings and heat
fusion
On an elevated pressure system, where are shut off valves required? - Answers Upstream of MP
regulator
What type of fittings can not be concealed? (7) - Answers Unions, bushings, regulators, shut off valves,
flex connectors, gas hoses, automatic valves
When using a meter for spot testing, how long should the half cubic foot dial be watched? - Answers 5
minutes
How is CSST protected from puncture threats? - Answers striker plates
How much earth cover must underground fuel lines have? - Answers 12"
, What should the test pressure be on a one PSI pressure system? - Answers 1.5x working pressure with 3
PSIG for 10 minutes
If the most remote appliance is 125 ft from the GM, what size branch line is needed for a 120,000 BTUH
furnace on a 4 oz. system located in SLC? - Answers 120,000/890 = 134 CFH = 1"
If an 80,000 BTUH Furnace is supplied with 890 BTU/CF gas, how many cubic ft of gas are required per
hour? - Answers 80,000/890 = 89.88 CFH
On a 2 PSI pressure system, how much gas will a 1 inch line carry 200 ft to a single appliance? - Answers
1,170 CFH
What pressure does a category IV vent system operate at? - Answers Above atmospheric or positive
If the most distant appliance in the Practice installation is 85 feet and the branch line to the furnace is 10
feet long, what is the minimum line size required on a 4 oz system? - Answers 1"
What is the maximum distance from an attic access to a furance? - Answers 20 feet
In a private garage, how far above the floor must an appliance's ignition source be located? - Answers 18
inches above the floor
What is the maximum input of an unvented room heater installed in a bedroom? - Answers 10,000
BTUH
What is the required volume criteria for an unvented room heater in a bathroom? - Answers 50 cubic
feet of volume for every 1,000 BTUH
What is the maximum length of a clothes dryer moister exhaust duct? - Answers 35 feet unless
authorized by clothes dryer manufacturer
What is the free area of a metal grill? - Answers 75% free area
What is the minimum cross-sectional dimension allowed in combustion air ducts? - Answers 3 inches
When is it permissible to screen vertical combustion air ducts? - Answers When it does not terminate in
an attic
If a room has a 30,000 BTUH water heater and a 100,000 BTUH Furnace, what is the minimum single
duct size that would satisfy code? - Answers 43.33 square inch
If a building is not of tight construction, what is the minimum required volume for an 80,000 BTUH
furnace and a 35,000 BTUH water heater? - Answers 115,000/1000x50 = 5750 cubic feet
If a basement contains a 75,000 BTUH furnace, 60,000 BTUH furnace, and a 40,000 BTUH water heater,
which of the following is the smallest that will satisfy the single combustion air duct requirement? -
Answers 175,000/3,000=58.33 square inch
How heavy is gasoline vapor? - Answers 2-4 times weight of air
What is the most harmful byproduct of combustion? - Answers Carbon Monoxide
What is the ignition temperature of natural gas? - Answers 1100-1200 degrees Farenheit
What is the density of propane vapor? - Answers 1.56
What are the byproducts of combustion? - Answers CO2, Water Vapor, Heat
What is the ratio for complete combustion of natural gas? - Answers 1 part natural gas to 10 part air
What is the maximum length of a flexible gas connector going to a furnace? - Answers 6 feet
What are the materials that can be used for piping natural gas? (4) - Answers Iron/steel, galvanize/black,
CSST, Polyethylene
What is an anode used for? - Answers To provide cathodic protection
What type of gas appliance is not require to have a shut off valve located in the same room? - Answers
Decorative appliance and room heaters
How close should a shut off valve be located to an appliance? - Answers Within 6 feet of the appliance
and in the same room
What is the minimum pipe size to a furnace and water heater location requested by Dominion? -
Answers 1"
What is the maximum pressure allowed before the use of welded joints is required? - Answers 5 PSIG
When is a tracer wire used? - Answers For underground non-metallic (plastic) gas lines
What methods can be used to join plastic gas pipe? - Answers Approved mechanical fittings and heat
fusion
On an elevated pressure system, where are shut off valves required? - Answers Upstream of MP
regulator
What type of fittings can not be concealed? (7) - Answers Unions, bushings, regulators, shut off valves,
flex connectors, gas hoses, automatic valves
When using a meter for spot testing, how long should the half cubic foot dial be watched? - Answers 5
minutes
How is CSST protected from puncture threats? - Answers striker plates
How much earth cover must underground fuel lines have? - Answers 12"
, What should the test pressure be on a one PSI pressure system? - Answers 1.5x working pressure with 3
PSIG for 10 minutes
If the most remote appliance is 125 ft from the GM, what size branch line is needed for a 120,000 BTUH
furnace on a 4 oz. system located in SLC? - Answers 120,000/890 = 134 CFH = 1"
If an 80,000 BTUH Furnace is supplied with 890 BTU/CF gas, how many cubic ft of gas are required per
hour? - Answers 80,000/890 = 89.88 CFH
On a 2 PSI pressure system, how much gas will a 1 inch line carry 200 ft to a single appliance? - Answers
1,170 CFH
What pressure does a category IV vent system operate at? - Answers Above atmospheric or positive
If the most distant appliance in the Practice installation is 85 feet and the branch line to the furnace is 10
feet long, what is the minimum line size required on a 4 oz system? - Answers 1"
What is the maximum distance from an attic access to a furance? - Answers 20 feet
In a private garage, how far above the floor must an appliance's ignition source be located? - Answers 18
inches above the floor
What is the maximum input of an unvented room heater installed in a bedroom? - Answers 10,000
BTUH
What is the required volume criteria for an unvented room heater in a bathroom? - Answers 50 cubic
feet of volume for every 1,000 BTUH
What is the maximum length of a clothes dryer moister exhaust duct? - Answers 35 feet unless
authorized by clothes dryer manufacturer
What is the free area of a metal grill? - Answers 75% free area
What is the minimum cross-sectional dimension allowed in combustion air ducts? - Answers 3 inches
When is it permissible to screen vertical combustion air ducts? - Answers When it does not terminate in
an attic
If a room has a 30,000 BTUH water heater and a 100,000 BTUH Furnace, what is the minimum single
duct size that would satisfy code? - Answers 43.33 square inch
If a building is not of tight construction, what is the minimum required volume for an 80,000 BTUH
furnace and a 35,000 BTUH water heater? - Answers 115,000/1000x50 = 5750 cubic feet
If a basement contains a 75,000 BTUH furnace, 60,000 BTUH furnace, and a 40,000 BTUH water heater,
which of the following is the smallest that will satisfy the single combustion air duct requirement? -
Answers 175,000/3,000=58.33 square inch
