HVAC Gas Heat Certification Exam
Questions and Answers
Question 1
A technician servicing an LP gas furnace notices a tag stating it was converted from
natural gas. He finds large amount of soot I'm the heat exchanger. What could be the
cause of this soot
Correct Answer
Orifice, (spud) too large
Question 2
On a dedicated vent system, a fire stop support plate is located
Correct Answer
Where it passes through a ceiling
Question 3
The most common burner used in induced draft furnace is
Correct Answer
Inshot
Question 4
Burning one cubic foot of natural gas will produce approximately _____ BTU's
Correct Answer
900~1,100
Question 5
Which of the following statements is true of nitrogen
Correct Answer
Nitrogen can combine with oxygen to form NOx
Page 1 of 20
,Question 6
Carbon monoxide is dangerous. What percentage of CO is acceptable in a sample of
the flue gas
Correct Answer
.04%
Question 7
A good description of how a bi-metal fan switch operates the blower motor on a gas
furnace is
Correct Answer
Temperature on- temperature off
Question 8
Which of the following must be present for combustion to occur
Correct Answer
Air, fuel and Ignition (Heat)
Question 9
A natural gas furnace usually requires _____ gas pressure at the manifold and burners
Correct Answer
3.5 in. W.C.
Question 10
Gas flow volume to natural gas furnace can be checked
Correct Answer
Using the gas meter installed at the site
Page 2 of 20
, Question 11
You have installed a Category IV two-pipe vent system that terminates through the
roof of the residence. The elbow for the combustion air intake, above the roof, should
Correct Answer
Point it down
Question 12
The "bonnet capacity" of a furnace is
Correct Answer
Furnace output BTU's
Question 13
The cut off plate is a component of the
Correct Answer
Blower housing
Question 14
A technician starts a spark type ignition furnace. The main burners light, but the spark
ignited continues to spark. After 60 seconds, the blower fan comes on and the burner
goes out. The technician suspects a faulty
Correct Answer
Ignition board
Question 15
Liquefied petroleum, (LP) gases are
Correct Answer
Propane and butane
Page 3 of 20
Questions and Answers
Question 1
A technician servicing an LP gas furnace notices a tag stating it was converted from
natural gas. He finds large amount of soot I'm the heat exchanger. What could be the
cause of this soot
Correct Answer
Orifice, (spud) too large
Question 2
On a dedicated vent system, a fire stop support plate is located
Correct Answer
Where it passes through a ceiling
Question 3
The most common burner used in induced draft furnace is
Correct Answer
Inshot
Question 4
Burning one cubic foot of natural gas will produce approximately _____ BTU's
Correct Answer
900~1,100
Question 5
Which of the following statements is true of nitrogen
Correct Answer
Nitrogen can combine with oxygen to form NOx
Page 1 of 20
,Question 6
Carbon monoxide is dangerous. What percentage of CO is acceptable in a sample of
the flue gas
Correct Answer
.04%
Question 7
A good description of how a bi-metal fan switch operates the blower motor on a gas
furnace is
Correct Answer
Temperature on- temperature off
Question 8
Which of the following must be present for combustion to occur
Correct Answer
Air, fuel and Ignition (Heat)
Question 9
A natural gas furnace usually requires _____ gas pressure at the manifold and burners
Correct Answer
3.5 in. W.C.
Question 10
Gas flow volume to natural gas furnace can be checked
Correct Answer
Using the gas meter installed at the site
Page 2 of 20
, Question 11
You have installed a Category IV two-pipe vent system that terminates through the
roof of the residence. The elbow for the combustion air intake, above the roof, should
Correct Answer
Point it down
Question 12
The "bonnet capacity" of a furnace is
Correct Answer
Furnace output BTU's
Question 13
The cut off plate is a component of the
Correct Answer
Blower housing
Question 14
A technician starts a spark type ignition furnace. The main burners light, but the spark
ignited continues to spark. After 60 seconds, the blower fan comes on and the burner
goes out. The technician suspects a faulty
Correct Answer
Ignition board
Question 15
Liquefied petroleum, (LP) gases are
Correct Answer
Propane and butane
Page 3 of 20
