MISSOURI HVAC SERVICE TECHNICIAN EXAM – QUESTIONS AND ANSWERS | VERIFIED AND WELL
DETAILED ANSWERS | PLUS RATIONALES | GUARANTEED PASS | LATEST EXAM UPDATE
Core Domains
1. Licensing and Regulatory Compliance (Missouri Local Jurisdictions)
2. Refrigeration Fundamentals and Thermodynamics
3. Heating Systems (Gas, Oil, Electric, Hydronic)
4. Air Distribution and Duct Design
5. Venting and Combustion Air
6. Electrical Components and Controls
7. System Installation, Maintenance, and Troubleshooting
8. Professional Standards and Safety
Introduction
This comprehensive examination is designed to rigorously assess the knowledge and practical skills required for
professional HVAC service technicians operating in the state of Missouri. The test evaluates a candidate's
understanding of fundamental thermodynamics, system component selection, and the application of complex
installation codes. It emphasizes real-world decision-making, from troubleshooting circulation issues to
ensuring combustion safety and compliance with local regulations. The format includes multiple-choice
questions and scenario-based problems that challenge the installer to apply theory to practical situations,
ensuring they are prepared to deliver efficient, safe, and reliable heating solutions in any residential or
commercial setting.
,SECTION ONE: QUESTIONS 1 – 100
1. As of 2026, which statement best describes HVAC licensing requirements in Missouri?
A. The state issues a single statewide HVAC contractor license through the Division of Professional
Registration
B. HVAC licensing is administered at the local municipal/county level, with no statewide HVAC license
C. Only the City of St. Louis requires HVAC licensing, while counties have no requirements
D. Missouri requires both a state license and a separate county license for all HVAC work
🟢B
🔴 Explanation: The correct answer is B. Missouri does not issue statewide HVAC contractor licenses. Unlike
electrical contracting, HVAC licensing is handled by individual cities and counties, with local boards
administering specific requirements .
2. In St. Louis County, which agency issues the Mechanical Contractor License?
A. Missouri Department of Labor
B. St. Louis County Department of Public Works
C. Board of Mechanical Examiners
D. OSHA
🟢C
🔴 Explanation: The correct answer is C. The Board of Mechanical Examiners reviews applications and issues
the license in St. Louis County, while the Department of Public Works enforces compliance .
3. How many hours of continuing education are required every three years to maintain a St. Louis County
mechanical contractor license?
A. 8 hours
,B. 12 hours
C. 24 hours
D. 36 hours
🟢C
🔴 Explanation: The correct answer is C. St. Louis County requires 24 hours (12 Professional Education
Units/PEUs) of approved continuing education every 3 years, with at least 6 hours in core topics and 6 hours
in trade topics .
4. A contractor plans to work in both St. Louis County and St. Charles County. What must they do regarding
licensing?
A. Obtain a single statewide license valid in both jurisdictions
B. Check requirements for each jurisdiction, as licensing requirements vary by municipality
C. Work only under a master contractor's license
D. Register with the Missouri Division of Professional Registration only
🟢B
🔴 Explanation: The correct answer is B. Since Missouri does not have a statewide HVAC license, contractors
must check licensing requirements for each city or county jurisdiction where they intend to work .
5. In Poplar Bluff, Missouri, what is the minimum experience requirement for a Class C mechanical installer
license?
A. 2 years
B. 4 years
C. 6 years
D. 8 years
, 🟢B
🔴 Explanation: The correct answer is B. Poplar Bluff requires Class C applicants to have proof of four years
of experience in the HVACR field. Class B requires six years, and Class A requires eight years .
6. What is the minimum insurance requirement for HVAC contractor licensing in St. Louis County?
A. $100,000 liability insurance only
B. $300,000 liability insurance and $5,000 surety bond
C. $500,000 liability insurance and $10,000 surety bond
D. $1,000,000 liability insurance only
🟢C
🔴 Explanation: The correct answer is C. Missouri requires HVAC contractors to carry $500,000 in liability
insurance and a surety bond of at least $10,000. Individual municipalities may have additional requirements
beyond these minimums .
7. An apprentice HVAC certification in Missouri:
A. Allows the holder to work independently on any HVAC system
B. Has no exam requirement and only allows work under supervision
C. Is issued by the EPA, not the local jurisdiction
D. Requires passing a 100-question exam
🟢B
🔴 Explanation: The correct answer is B. The apprentice HVAC certification allows work only under the
supervision of a licensed contractor or journeyman. There is no apprentice exam; applicants must complete
an approved training program and apply for the certification .
DETAILED ANSWERS | PLUS RATIONALES | GUARANTEED PASS | LATEST EXAM UPDATE
Core Domains
1. Licensing and Regulatory Compliance (Missouri Local Jurisdictions)
2. Refrigeration Fundamentals and Thermodynamics
3. Heating Systems (Gas, Oil, Electric, Hydronic)
4. Air Distribution and Duct Design
5. Venting and Combustion Air
6. Electrical Components and Controls
7. System Installation, Maintenance, and Troubleshooting
8. Professional Standards and Safety
Introduction
This comprehensive examination is designed to rigorously assess the knowledge and practical skills required for
professional HVAC service technicians operating in the state of Missouri. The test evaluates a candidate's
understanding of fundamental thermodynamics, system component selection, and the application of complex
installation codes. It emphasizes real-world decision-making, from troubleshooting circulation issues to
ensuring combustion safety and compliance with local regulations. The format includes multiple-choice
questions and scenario-based problems that challenge the installer to apply theory to practical situations,
ensuring they are prepared to deliver efficient, safe, and reliable heating solutions in any residential or
commercial setting.
,SECTION ONE: QUESTIONS 1 – 100
1. As of 2026, which statement best describes HVAC licensing requirements in Missouri?
A. The state issues a single statewide HVAC contractor license through the Division of Professional
Registration
B. HVAC licensing is administered at the local municipal/county level, with no statewide HVAC license
C. Only the City of St. Louis requires HVAC licensing, while counties have no requirements
D. Missouri requires both a state license and a separate county license for all HVAC work
🟢B
🔴 Explanation: The correct answer is B. Missouri does not issue statewide HVAC contractor licenses. Unlike
electrical contracting, HVAC licensing is handled by individual cities and counties, with local boards
administering specific requirements .
2. In St. Louis County, which agency issues the Mechanical Contractor License?
A. Missouri Department of Labor
B. St. Louis County Department of Public Works
C. Board of Mechanical Examiners
D. OSHA
🟢C
🔴 Explanation: The correct answer is C. The Board of Mechanical Examiners reviews applications and issues
the license in St. Louis County, while the Department of Public Works enforces compliance .
3. How many hours of continuing education are required every three years to maintain a St. Louis County
mechanical contractor license?
A. 8 hours
,B. 12 hours
C. 24 hours
D. 36 hours
🟢C
🔴 Explanation: The correct answer is C. St. Louis County requires 24 hours (12 Professional Education
Units/PEUs) of approved continuing education every 3 years, with at least 6 hours in core topics and 6 hours
in trade topics .
4. A contractor plans to work in both St. Louis County and St. Charles County. What must they do regarding
licensing?
A. Obtain a single statewide license valid in both jurisdictions
B. Check requirements for each jurisdiction, as licensing requirements vary by municipality
C. Work only under a master contractor's license
D. Register with the Missouri Division of Professional Registration only
🟢B
🔴 Explanation: The correct answer is B. Since Missouri does not have a statewide HVAC license, contractors
must check licensing requirements for each city or county jurisdiction where they intend to work .
5. In Poplar Bluff, Missouri, what is the minimum experience requirement for a Class C mechanical installer
license?
A. 2 years
B. 4 years
C. 6 years
D. 8 years
, 🟢B
🔴 Explanation: The correct answer is B. Poplar Bluff requires Class C applicants to have proof of four years
of experience in the HVACR field. Class B requires six years, and Class A requires eight years .
6. What is the minimum insurance requirement for HVAC contractor licensing in St. Louis County?
A. $100,000 liability insurance only
B. $300,000 liability insurance and $5,000 surety bond
C. $500,000 liability insurance and $10,000 surety bond
D. $1,000,000 liability insurance only
🟢C
🔴 Explanation: The correct answer is C. Missouri requires HVAC contractors to carry $500,000 in liability
insurance and a surety bond of at least $10,000. Individual municipalities may have additional requirements
beyond these minimums .
7. An apprentice HVAC certification in Missouri:
A. Allows the holder to work independently on any HVAC system
B. Has no exam requirement and only allows work under supervision
C. Is issued by the EPA, not the local jurisdiction
D. Requires passing a 100-question exam
🟢B
🔴 Explanation: The correct answer is B. The apprentice HVAC certification allows work only under the
supervision of a licensed contractor or journeyman. There is no apprentice exam; applicants must complete
an approved training program and apply for the certification .
