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NATE Gas & Heat Newest Exam 2025 / NATE
Gas & Heat Preparation/NATE Gas & Heat
Exam Practice Exam With 300 Questions And
Correct Answers| Brand New Version!
What type of furnace is commonly installed in a closet with
underfloor supply ducts?
a. Downflow
b. Horizontal
c. Lowboy
d. Upflow - ..........ANSWER.......a (Downflow)
Which of the following is required for combustion?
a. Fuel
b. Heat
c. Oxygen
d. All of the above - ..........ANSWER.......d (All of the above)
Which of the following is NOT a product of complete combustion?
a. Carbon dioxide
b. Carbon monoxide
c. Heat
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d. Water - ..........ANSWER.......b (Carbon monoxide)
An unconfined space (in terms of furnace installation) is defined as a
space with a volume equal to or greater than ______ per 1,000 Btu of
input rating.
a. 25 ft.3
b. 50 ft.3
c. 75 ft.3
d. 100 ft.3 - ..........ANSWER.......b
Combustion air may be added to a confined space by a duct to the
outside, sized on an input of 1 in.2 per _____.
a. 1,000 Btu
b. 2,000 Btu
c. 4,000 Btu
d. 5,000 Btu - ..........ANSWER.......d
What type of burners are commonly used with induced-draft gas
furnaces?
a. Gun style
b. Pot style
c. Ribbon
d. Inshot - ..........ANSWER.......d
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What is the typical color of a properly burning gas flame?
a. Blue
b. Orange
c. Red
d. Yellow - ..........ANSWER.......a
In a gas furnace, primary combustion air is introduced in the _______.
a. burner prior to ignition
b. burner after ignition
c. gas line
d. heat exchanger - ..........ANSWER.......a
A "dumbbell" style CO2 tester ________.
a. contains a test fluid that absorbs CO2
b. measures CO2 in parts per million
c. provides a digital readout
d. requires a power supply - ..........ANSWER.......a
Useful heat output, expressed as a percentage of the total burner
input, is known as the ______ of a gas furnace.
a. combustion efficiency
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b. fuel efficiency
c. heat exchanger performance factor
d. heating coefficient - ..........ANSWER.......a
Which type of ignition system uses a thermocouple?
a. Direct ignition
b. Hot-surface
c. Intermittent ignition
d. Standing pilot - ..........ANSWER.......d
The blower in a standing pilot furnace is generally started by a(n)
______.
a. differential pressure switch
b. ignition module
c. temperature switch
d. time-delay relay - ..........ANSWER.......c
A furnace with an induced-draft fan uses a _______ to prove air flow.
a. high-pressure switch
b. low-pressure switch
c. pressure differential switch
d. sail switch - ..........ANSWER.......c
NATE Gas & Heat Newest Exam 2025 / NATE
Gas & Heat Preparation/NATE Gas & Heat
Exam Practice Exam With 300 Questions And
Correct Answers| Brand New Version!
What type of furnace is commonly installed in a closet with
underfloor supply ducts?
a. Downflow
b. Horizontal
c. Lowboy
d. Upflow - ..........ANSWER.......a (Downflow)
Which of the following is required for combustion?
a. Fuel
b. Heat
c. Oxygen
d. All of the above - ..........ANSWER.......d (All of the above)
Which of the following is NOT a product of complete combustion?
a. Carbon dioxide
b. Carbon monoxide
c. Heat
,2|Page
d. Water - ..........ANSWER.......b (Carbon monoxide)
An unconfined space (in terms of furnace installation) is defined as a
space with a volume equal to or greater than ______ per 1,000 Btu of
input rating.
a. 25 ft.3
b. 50 ft.3
c. 75 ft.3
d. 100 ft.3 - ..........ANSWER.......b
Combustion air may be added to a confined space by a duct to the
outside, sized on an input of 1 in.2 per _____.
a. 1,000 Btu
b. 2,000 Btu
c. 4,000 Btu
d. 5,000 Btu - ..........ANSWER.......d
What type of burners are commonly used with induced-draft gas
furnaces?
a. Gun style
b. Pot style
c. Ribbon
d. Inshot - ..........ANSWER.......d
,3|Page
What is the typical color of a properly burning gas flame?
a. Blue
b. Orange
c. Red
d. Yellow - ..........ANSWER.......a
In a gas furnace, primary combustion air is introduced in the _______.
a. burner prior to ignition
b. burner after ignition
c. gas line
d. heat exchanger - ..........ANSWER.......a
A "dumbbell" style CO2 tester ________.
a. contains a test fluid that absorbs CO2
b. measures CO2 in parts per million
c. provides a digital readout
d. requires a power supply - ..........ANSWER.......a
Useful heat output, expressed as a percentage of the total burner
input, is known as the ______ of a gas furnace.
a. combustion efficiency
, 4|Page
b. fuel efficiency
c. heat exchanger performance factor
d. heating coefficient - ..........ANSWER.......a
Which type of ignition system uses a thermocouple?
a. Direct ignition
b. Hot-surface
c. Intermittent ignition
d. Standing pilot - ..........ANSWER.......d
The blower in a standing pilot furnace is generally started by a(n)
______.
a. differential pressure switch
b. ignition module
c. temperature switch
d. time-delay relay - ..........ANSWER.......c
A furnace with an induced-draft fan uses a _______ to prove air flow.
a. high-pressure switch
b. low-pressure switch
c. pressure differential switch
d. sail switch - ..........ANSWER.......c
