CALIFORNIA HVAC CONTRACTOR EXAMINATION – PRACTICE QUESTIONS
AND CORRECT ANSWERS (VERIFIED ANSWERS) PLUS RATIONALES 2026
Q&A | INSTANT DOWNLOAD PDF.
CORE DOMAINS
1. Business and Financial Management
2. Safety and Cal/OSHA Compliance
3. HVAC System Design and Engineering
4. Installation and Start-up Procedures
5. Maintenance and Repair Diagnosis
6. Title 24 Energy Efficiency Standards
7. Refrigerant Management and EPA Regulations
8. Venting and Combustion Air Requirements
9. Electrical Theory and Controls
10. Project Estimating and Contract Law
INTRODUCTION
The purpose of this examination is to evaluate the competency of individuals seeking
a C-20 HVAC license in California. This assessment covers a broad spectrum of
critical skills, including technical proficiency in mechanical systems, adherence to strict
state-mandated energy codes, and ethical business practices. The examination is
structured using multiple-choice and scenario-based questions that mirror real-world
challenges encountered by contractors in the field. Candidates are tested on their
ability to make informed decisions regarding system sizing, safety protocols, and
regulatory compliance. This comprehensive tool emphasizes practical application,
,ensuring that licensed professionals maintain the highest standards of safety and
efficiency within the industry.
SECTION ONE
1. What is the maximum distance a ladder should extend above the roof line or
support point?
A. 1 foot
B. 2 feet
🟢 C. 3 feet
D. 5 feet
🔴 RATIONALE: Per Cal/OSHA safety standards, ladders must extend at least 3 feet
above the point of support or roof line to provide a safe handhold for workers
transitioning to or from the roof.
2. According to Title 24, what is the maximum allowed leakage for a new duct
system in a residential retrofit?
🟢 A. 5%
B. 10%
C. 15%
D. 22%
🔴 RATIONALE: Under California’s Energy Code (Title 24, Part 6), new duct systems
or replaced duct systems in residential buildings are generally limited to a leakage rate
of 5% or less when tested with a duct blaster.
3. Which of the following describes the "latent heat of vaporization"?
,A. The heat required to raise the temperature of a liquid without changing its state.
B. The heat released when a gas turns into a solid.
🟢 C. The heat required to change a liquid into a gas without a change in
temperature.
D. The heat removed to lower the temperature of a vapor.
🔴 RATIONALE: Latent heat of vaporization refers to the energy absorbed by a
substance to transition from the liquid phase to the vapor phase while the temperature
remains constant.
4. A technician is troubleshooting a split system where the compressor is running
but the indoor blower is not. What is the most likely cause?
A. Blown fuse in the outdoor disconnect.
B. Faulty high-pressure switch.
🟢 C. Failed blower motor capacitor or relay.
D. Clogged filter drier.
🔴 RATIONALE: If the compressor operates, the primary control circuit is likely
closed; the failure of the indoor blower specifically points to a component in the air
handler circuit, such as the motor, capacitor, or relay.
5. When installing a gas furnace in a closet, what is the requirement for combustion
air?
A. No air is needed if the door is louvered.
🟢 B. Two permanent openings, one within 12 inches of the top and one within 12
inches of the bottom.
C. One opening located at exactly 36 inches from the floor.
, D. A single opening of 50 square inches regardless of BTU rating.
🔴 RATIONALE: The California Mechanical Code requires two openings for
permanent combustion air to ensure proper airflow for combustion and dilution of flue
gases in confined spaces.
6. What is the effect of an undersized suction line on a cooling system?
A. Increased cooling capacity.
🟢 B. Reduced system efficiency and potential compressor overheating.
C. Increased refrigerant flow rate.
D. Lowered head pressure.
🔴 RATIONALE: An undersized suction line creates excessive pressure drop,
reducing the density of the refrigerant entering the compressor, which lowers capacity
and limits the cooling of the compressor motor.
7. Under California law, a home improvement contract must include which of the
following?
A. The contractor's social security number.
B. A list of all the contractor's previous clients.
🟢 C. A "Notice to Owner" regarding mechanics' liens.
D. A guaranteed completion date within 10 days of signing.
🔴 RATIONALE: The Contractors State License Board (CSLB) requires a specific
notice regarding mechanics' liens to protect homeowners by informing them how to
prevent liens on their property.
8. In a series circuit with three resistors of 10, 20, and 30 ohms, what is the total
resistance?
AND CORRECT ANSWERS (VERIFIED ANSWERS) PLUS RATIONALES 2026
Q&A | INSTANT DOWNLOAD PDF.
CORE DOMAINS
1. Business and Financial Management
2. Safety and Cal/OSHA Compliance
3. HVAC System Design and Engineering
4. Installation and Start-up Procedures
5. Maintenance and Repair Diagnosis
6. Title 24 Energy Efficiency Standards
7. Refrigerant Management and EPA Regulations
8. Venting and Combustion Air Requirements
9. Electrical Theory and Controls
10. Project Estimating and Contract Law
INTRODUCTION
The purpose of this examination is to evaluate the competency of individuals seeking
a C-20 HVAC license in California. This assessment covers a broad spectrum of
critical skills, including technical proficiency in mechanical systems, adherence to strict
state-mandated energy codes, and ethical business practices. The examination is
structured using multiple-choice and scenario-based questions that mirror real-world
challenges encountered by contractors in the field. Candidates are tested on their
ability to make informed decisions regarding system sizing, safety protocols, and
regulatory compliance. This comprehensive tool emphasizes practical application,
,ensuring that licensed professionals maintain the highest standards of safety and
efficiency within the industry.
SECTION ONE
1. What is the maximum distance a ladder should extend above the roof line or
support point?
A. 1 foot
B. 2 feet
🟢 C. 3 feet
D. 5 feet
🔴 RATIONALE: Per Cal/OSHA safety standards, ladders must extend at least 3 feet
above the point of support or roof line to provide a safe handhold for workers
transitioning to or from the roof.
2. According to Title 24, what is the maximum allowed leakage for a new duct
system in a residential retrofit?
🟢 A. 5%
B. 10%
C. 15%
D. 22%
🔴 RATIONALE: Under California’s Energy Code (Title 24, Part 6), new duct systems
or replaced duct systems in residential buildings are generally limited to a leakage rate
of 5% or less when tested with a duct blaster.
3. Which of the following describes the "latent heat of vaporization"?
,A. The heat required to raise the temperature of a liquid without changing its state.
B. The heat released when a gas turns into a solid.
🟢 C. The heat required to change a liquid into a gas without a change in
temperature.
D. The heat removed to lower the temperature of a vapor.
🔴 RATIONALE: Latent heat of vaporization refers to the energy absorbed by a
substance to transition from the liquid phase to the vapor phase while the temperature
remains constant.
4. A technician is troubleshooting a split system where the compressor is running
but the indoor blower is not. What is the most likely cause?
A. Blown fuse in the outdoor disconnect.
B. Faulty high-pressure switch.
🟢 C. Failed blower motor capacitor or relay.
D. Clogged filter drier.
🔴 RATIONALE: If the compressor operates, the primary control circuit is likely
closed; the failure of the indoor blower specifically points to a component in the air
handler circuit, such as the motor, capacitor, or relay.
5. When installing a gas furnace in a closet, what is the requirement for combustion
air?
A. No air is needed if the door is louvered.
🟢 B. Two permanent openings, one within 12 inches of the top and one within 12
inches of the bottom.
C. One opening located at exactly 36 inches from the floor.
, D. A single opening of 50 square inches regardless of BTU rating.
🔴 RATIONALE: The California Mechanical Code requires two openings for
permanent combustion air to ensure proper airflow for combustion and dilution of flue
gases in confined spaces.
6. What is the effect of an undersized suction line on a cooling system?
A. Increased cooling capacity.
🟢 B. Reduced system efficiency and potential compressor overheating.
C. Increased refrigerant flow rate.
D. Lowered head pressure.
🔴 RATIONALE: An undersized suction line creates excessive pressure drop,
reducing the density of the refrigerant entering the compressor, which lowers capacity
and limits the cooling of the compressor motor.
7. Under California law, a home improvement contract must include which of the
following?
A. The contractor's social security number.
B. A list of all the contractor's previous clients.
🟢 C. A "Notice to Owner" regarding mechanics' liens.
D. A guaranteed completion date within 10 days of signing.
🔴 RATIONALE: The Contractors State License Board (CSLB) requires a specific
notice regarding mechanics' liens to protect homeowners by informing them how to
prevent liens on their property.
8. In a series circuit with three resistors of 10, 20, and 30 ohms, what is the total
resistance?
