DC Heating Contractor Exam Practice
Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1. Which of the following is the primary responsibility of a DC Heating
Contractor when installing a new heating system?
A. Selecting decorative finishes for mechanical rooms
B. Ensuring the system is safely designed, installed, and compliant with
applicable codes
C. Training only the building owner’s employees
D. Purchasing fuel from local suppliers
Correct Answer: B
A heating contractor is responsible for proper system design, installation,
safety compliance, and adherence to mechanical, fuel, and building codes
governing heating equipment.
2. Which code is most commonly used as a basis for regulating heating
system installations in the District of Columbia?
A. National Electrical Code only
B. International Mechanical Code
C. Food and Drug Administration Code
D. Highway Construction Code
,Correct Answer: B
The International Mechanical Code provides requirements for mechanical
systems, including heating equipment installation, ventilation, and safety
provisions.
3. Before installing a heating appliance, a contractor should first
determine:
A. The color of the equipment cabinet
B. The heating load requirements of the building
C. The homeowner’s preferred thermostat brand
D. The location of furniture in the rooms
Correct Answer: B
Heating load calculations determine the required capacity of equipment to
provide adequate comfort without excessive energy consumption.
4. What is the purpose of a Manual J load calculation?
A. Measuring electrical resistance
B. Determining residential heating and cooling loads
C. Testing fuel quality
D. Calculating pipe thread dimensions
Correct Answer: B
Manual J procedures calculate the amount of heating and cooling required
based on building characteristics, insulation, windows, and climate
conditions.
5. A furnace that is oversized for a building will most likely:
A. Operate more efficiently at all times
B. Cycle on and off frequently
,C. Produce no heat
D. Require no maintenance
Correct Answer: B
Oversized heating equipment often short cycles, causing reduced efficiency,
uneven temperatures, and increased component wear.
6. What component transfers heat from combustion gases to air in a
forced-air furnace?
A. Expansion valve
B. Heat exchanger
C. Condenser coil
D. Evaporator fan
Correct Answer: B
The heat exchanger separates combustion gases from conditioned air while
transferring heat into the air stream.
7. A cracked furnace heat exchanger can create a danger of:
A. Reduced water pressure
B. Carbon monoxide leakage
C. Increased refrigerant charge
D. Excessive electrical voltage
Correct Answer: B
A damaged heat exchanger may allow combustion gases containing
carbon monoxide to enter occupied spaces.
8. What instrument is commonly used to test for carbon monoxide levels
in heating systems?
A. Multimeter
B. CO analyzer
, C. Tape measure
D. Pipe wrench
Correct Answer: B
A carbon monoxide analyzer measures CO concentration and helps verify
safe combustion operation.
9. The purpose of a draft inducer motor in a modern furnace is to:
A. Increase room humidity
B. Establish proper combustion airflow
C. Cool the thermostat
D. Reduce electrical voltage
Correct Answer: B
The draft inducer creates proper airflow through the heat exchanger and
venting system before ignition.
10. A flame sensor in a gas furnace is designed to:
A. Measure room temperature
B. Confirm burner flame presence
C. Increase gas pressure
D. Control blower speed only
Correct Answer: B
The flame sensor proves that ignition has occurred and shuts off gas flow if
flame is not detected.
11. What is the purpose of a thermostat in a heating system?
A. Store fuel
B. Sense temperature and control operation
C. Increase airflow pressure
D. Filter combustion gases
Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1. Which of the following is the primary responsibility of a DC Heating
Contractor when installing a new heating system?
A. Selecting decorative finishes for mechanical rooms
B. Ensuring the system is safely designed, installed, and compliant with
applicable codes
C. Training only the building owner’s employees
D. Purchasing fuel from local suppliers
Correct Answer: B
A heating contractor is responsible for proper system design, installation,
safety compliance, and adherence to mechanical, fuel, and building codes
governing heating equipment.
2. Which code is most commonly used as a basis for regulating heating
system installations in the District of Columbia?
A. National Electrical Code only
B. International Mechanical Code
C. Food and Drug Administration Code
D. Highway Construction Code
,Correct Answer: B
The International Mechanical Code provides requirements for mechanical
systems, including heating equipment installation, ventilation, and safety
provisions.
3. Before installing a heating appliance, a contractor should first
determine:
A. The color of the equipment cabinet
B. The heating load requirements of the building
C. The homeowner’s preferred thermostat brand
D. The location of furniture in the rooms
Correct Answer: B
Heating load calculations determine the required capacity of equipment to
provide adequate comfort without excessive energy consumption.
4. What is the purpose of a Manual J load calculation?
A. Measuring electrical resistance
B. Determining residential heating and cooling loads
C. Testing fuel quality
D. Calculating pipe thread dimensions
Correct Answer: B
Manual J procedures calculate the amount of heating and cooling required
based on building characteristics, insulation, windows, and climate
conditions.
5. A furnace that is oversized for a building will most likely:
A. Operate more efficiently at all times
B. Cycle on and off frequently
,C. Produce no heat
D. Require no maintenance
Correct Answer: B
Oversized heating equipment often short cycles, causing reduced efficiency,
uneven temperatures, and increased component wear.
6. What component transfers heat from combustion gases to air in a
forced-air furnace?
A. Expansion valve
B. Heat exchanger
C. Condenser coil
D. Evaporator fan
Correct Answer: B
The heat exchanger separates combustion gases from conditioned air while
transferring heat into the air stream.
7. A cracked furnace heat exchanger can create a danger of:
A. Reduced water pressure
B. Carbon monoxide leakage
C. Increased refrigerant charge
D. Excessive electrical voltage
Correct Answer: B
A damaged heat exchanger may allow combustion gases containing
carbon monoxide to enter occupied spaces.
8. What instrument is commonly used to test for carbon monoxide levels
in heating systems?
A. Multimeter
B. CO analyzer
, C. Tape measure
D. Pipe wrench
Correct Answer: B
A carbon monoxide analyzer measures CO concentration and helps verify
safe combustion operation.
9. The purpose of a draft inducer motor in a modern furnace is to:
A. Increase room humidity
B. Establish proper combustion airflow
C. Cool the thermostat
D. Reduce electrical voltage
Correct Answer: B
The draft inducer creates proper airflow through the heat exchanger and
venting system before ignition.
10. A flame sensor in a gas furnace is designed to:
A. Measure room temperature
B. Confirm burner flame presence
C. Increase gas pressure
D. Control blower speed only
Correct Answer: B
The flame sensor proves that ignition has occurred and shuts off gas flow if
flame is not detected.
11. What is the purpose of a thermostat in a heating system?
A. Store fuel
B. Sense temperature and control operation
C. Increase airflow pressure
D. Filter combustion gases
