NATE Gas Heating Exam Comprehensive Questions And Correct Answers.

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NATE Gas Heating Exam 2026-2027
Comprehensive Questions And
Correct Answers


Carbon monoxide is a:


A: Product of incomplete combustion


B: Poisonous gas


C: Odorless gas


D: All of the above are correct - correct-answer -D: All of the above are correct




The chemical symbol for carbon monoxide is:


A: CO2


B: CO

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C: H2O


D: NH3 - correct-answer -B: CO




Selecting a lower speed tap setting on a furnace indoor blower motor will cause:


A: The temperature rise through the furnace to increase


B: The temperature rise through the furnace to decrease


C: The temperature rise through the furnace will not be affected


D: The furnace to act as a humidifier - correct-answer -A: The temperature rise
through the furnace to increase




"Carry over" channels or "cross overs" are used to:


A: Carry unused excess fuel back to the flue where it is sent up the stack


B: Carry primary air to the heat exchanger

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C: Carry secondary air to the heat exchanger


D: Carry the flame from the first burner that lights to the remaining burners -
correct-answer -D: Carry the flame from the first burner that lights to the
remaining burners




Modern high-efficiency burners use combustion blowers. What are the two major
types of combustion blowers?


A: Induced draft and forced draft


B: High pressure and low pressure


C: Impeller type and centrifugal type


D: Liquid and vapor types - correct-answer -A: Induced draft and forced draft




The purpose of the combustion blower is to:


A: Cause an adequate amount of oxygen-rich air to mix with the fuel for better
combustion