South Carolina Combustion Technician
Certification License Exam Practice
Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1. The primary purpose of the South Carolina Combustion Technician
Certification program is to ensure technicians are competent in the
safe and efficient operation of combustion equipment. Which of the
following best describes this purpose?
A. To increase sales of combustion systems
B. To protect public health, safety, and property
C. To standardize pricing of combustion services
D. To limit market competition among technicians
The certification is designed to ensure technicians can safely install
and maintain combustion systems to protect people and property.
2. According to standard combustion safety practices, what is the
minimum required air-to-fuel ratio for complete combustion of natural
gas?
A. 5:1
B. 10:1
C. 15:1
D. 20:1
A 10:1 air-to-fuel ratio is the typical minimum required to achieve
complete combustion of natural gas under standard conditions.
3. Which of the following gases is primarily measured to assess
combustion efficiency?
, A. Nitrogen
B. Oxygen
C. Carbon Monoxide
D. Hydrogen
Carbon monoxide levels are a key indicator of incomplete
combustion and are used to evaluate combustion efficiency.
4. What is the function of a flame sensor in a combustion system?
A. To regulate fuel flow
B. To measure combustion temperature
C. To detect the presence of a flame
D. To monitor exhaust pressure
A flame sensor confirms that ignition has occurred and a flame is
present to ensure safe system operation.
5. In South Carolina’s regulations, what is the minimum safe clearance
required between a combustion appliance and combustible materials?
A. 1 inch
B. 3 inches
C. 6 inches
D. 12 inches
Combustion appliances typically require at least a 6-inch clearance
from combustible materials to reduce fire hazards.
6. Which class of fire extinguisher is appropriate for a fire involving
combustible gases?
A. Class A
B. Class B
C. Class C
D. Class D
Class C extinguishers are rated for fires involving energized electrical
equipment, but for combustible gases in a mechanical room, a
multi-use ABC rated extinguisher is appropriate; however the answer
reflecting gas involvement is C due to ignition source considerations.
7. What type of fuel is most commonly used in commercial combustion
systems in South Carolina?
A. Propane
B. Fuel oil
, C. Natural gas
D. Coal
Natural gas is widely available and commonly used for commercial
combustion systems in South Carolina.
8. Which instrument is used to measure the oxygen content in flue
gases?
A. Thermocouple
B. Combustion analyzer
C. Manometer
D. Pressure gauge
A combustion analyzer measures concentrations of gases such as
oxygen in flue products to assess combustion conditions.
9. When adjusting a burner, what is the effect of increasing primary air?
A. Richer mixture
B. Leaner mixture
C. No effect
D. Reduced flame stability
Increasing primary air adds more oxygen to the mixture, making it
leaner.
10. What is flashback in a combustion system?
A. A sudden loss of flame
B. A flame front moving back into the burner
C. Excess air entering the combustion chamber
D. A failed ignition spark
Flashback occurs when the flame travels back into the burner, which
can be dangerous and indicates improper settings.
11. The Lower Explosive Limit (LEL) for methane is approximately:
A. 2%
B. 4%
C. 5%
D. 10%
Methane has an LEL around 5%, below which it will not ignite.
12. The purpose of a draft inducer is to:
A. Increase fuel flow
B. Promote proper venting of combustion gases
Certification License Exam Practice
Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1. The primary purpose of the South Carolina Combustion Technician
Certification program is to ensure technicians are competent in the
safe and efficient operation of combustion equipment. Which of the
following best describes this purpose?
A. To increase sales of combustion systems
B. To protect public health, safety, and property
C. To standardize pricing of combustion services
D. To limit market competition among technicians
The certification is designed to ensure technicians can safely install
and maintain combustion systems to protect people and property.
2. According to standard combustion safety practices, what is the
minimum required air-to-fuel ratio for complete combustion of natural
gas?
A. 5:1
B. 10:1
C. 15:1
D. 20:1
A 10:1 air-to-fuel ratio is the typical minimum required to achieve
complete combustion of natural gas under standard conditions.
3. Which of the following gases is primarily measured to assess
combustion efficiency?
, A. Nitrogen
B. Oxygen
C. Carbon Monoxide
D. Hydrogen
Carbon monoxide levels are a key indicator of incomplete
combustion and are used to evaluate combustion efficiency.
4. What is the function of a flame sensor in a combustion system?
A. To regulate fuel flow
B. To measure combustion temperature
C. To detect the presence of a flame
D. To monitor exhaust pressure
A flame sensor confirms that ignition has occurred and a flame is
present to ensure safe system operation.
5. In South Carolina’s regulations, what is the minimum safe clearance
required between a combustion appliance and combustible materials?
A. 1 inch
B. 3 inches
C. 6 inches
D. 12 inches
Combustion appliances typically require at least a 6-inch clearance
from combustible materials to reduce fire hazards.
6. Which class of fire extinguisher is appropriate for a fire involving
combustible gases?
A. Class A
B. Class B
C. Class C
D. Class D
Class C extinguishers are rated for fires involving energized electrical
equipment, but for combustible gases in a mechanical room, a
multi-use ABC rated extinguisher is appropriate; however the answer
reflecting gas involvement is C due to ignition source considerations.
7. What type of fuel is most commonly used in commercial combustion
systems in South Carolina?
A. Propane
B. Fuel oil
, C. Natural gas
D. Coal
Natural gas is widely available and commonly used for commercial
combustion systems in South Carolina.
8. Which instrument is used to measure the oxygen content in flue
gases?
A. Thermocouple
B. Combustion analyzer
C. Manometer
D. Pressure gauge
A combustion analyzer measures concentrations of gases such as
oxygen in flue products to assess combustion conditions.
9. When adjusting a burner, what is the effect of increasing primary air?
A. Richer mixture
B. Leaner mixture
C. No effect
D. Reduced flame stability
Increasing primary air adds more oxygen to the mixture, making it
leaner.
10. What is flashback in a combustion system?
A. A sudden loss of flame
B. A flame front moving back into the burner
C. Excess air entering the combustion chamber
D. A failed ignition spark
Flashback occurs when the flame travels back into the burner, which
can be dangerous and indicates improper settings.
11. The Lower Explosive Limit (LEL) for methane is approximately:
A. 2%
B. 4%
C. 5%
D. 10%
Methane has an LEL around 5%, below which it will not ignite.
12. The purpose of a draft inducer is to:
A. Increase fuel flow
B. Promote proper venting of combustion gases
