Connecticut Unlimited Heating, Piping and Cooling Journeyperson (S-2) Exam Book Package

Prepare for the Connecticut Unlimited Heating, Piping and Cooling Journeyperson (S-2) examination with a comprehensive package that combines the approved exam-room references with supplemental technical books for deeper study. This collection supports preparation across fuel-gas systems, hydronics, oil burners, refrigeration, air conditioning, boilers, ductwork, controls, ventilation, combustion air, steam systems, construction safety, and mechanical installation requirements.

The Connecticut S-2 examination covers a wide range of heating, piping, and cooling work. Candidates must understand practical trade concepts while also knowing how to locate code requirements, technical explanations, sizing tables, equipment information, diagrams, definitions, and safety provisions during a timed open-book test.

This package includes the International Mechanical Code, 2021; NFPA 54 - National Fuel Gas Code Handbook, 2012; NFPA 31: Standard for the Installation of Oil-Burning Equipment, 2011; Code of Federal Regulations - 29 CFR Part 1926 (OSHA); Modern Refrigeration and Air Conditioning, 22nd Edition; a Ductulator; HVAC Duct Construction Standards, Metal and Flexible, 2005, 3rd Edition; NFPA 58 - Liquefied Petroleum Gas Code, 2014; and NFPA 56: Standard for Fire and Explosion Prevention During Cleaning and Purging of Flammable Gas Piping, 2023.

The package also includes Modern Hydronic Heating for Residential and Light Commercial Buildings by John Siegenthaler, P.E., 2022; Residential Oil Burners, 3rd Edition; and Steam Plant Operation, 10th Edition, 2017. These supplemental study books provide additional explanations involving hydronic system design, oil-burner operation, boilers, steam generation, controls, circulation, maintenance, and troubleshooting.

The approved exam-room references address the codes, standards, safety rules, technical subjects, and calculation tools associated with the S-2 examination. The supplemental books help candidates strengthen the underlying trade knowledge needed to interpret those requirements and apply them to practical situations.

Because the S-2 examination is open book, candidates should use the approved references throughout preparation. The number of books makes it important to identify the main subject before beginning a search. Candidates should know whether a question belongs in the mechanical code, natural-gas standard, oil-burning standard, LP gas code, duct-construction reference, safety regulations, refrigeration textbook, or gas-piping safety standard.

This product is a standard exam book package. It does not include highlighting and tabbing services, online course access, book rental, Application Service, or a refundable deposit.

Exam Details

The Connecticut Unlimited Heating, Piping and Cooling Journeyperson (S-2) examination contains 70 questions. Candidates are allowed three hours to complete the examination, and a minimum score of 70 percent is required to pass.

The S-2 examination content outline includes the following subject areas:

• Insulation: 1 question
• Hangers and Supports: 2 questions
• Sound, Vibration and Seismic Control: 1 question
• Heating and Cooling Principles: 4 questions
• Refrigerants and Refrigeration: 5 questions
• Testing, Adjusting and Balancing: 1 question
• Controls: 4 questions
• Machine Room: 1 question
• Air-Conditioning and Heat-Pump Equipment: 3 questions
• Furnaces and Heaters: 4 questions
• Hydronics: 6 questions
• Chimneys, Flues and Vents: 3 questions
• Combustion Air: 2 questions
• Fuel Gas Systems: 10 questions
• Ducts: 6 questions
• Chillers: 2 questions
• Ventilation and Exhaust: 2 questions
• Safety: 4 questions
• Oil Burners: 6 questions
• Boilers: 3 questions

Fuel-gas systems are the largest examination category, accounting for 10 of the 70 questions. Candidates should understand natural-gas piping materials, system demand, sizing, regulators, appliance connections, pressure, testing, combustion air, venting, cleaning, purging, and related safety requirements.

Gas-pipe sizing questions require use of the longest-length method. Candidates should practice identifying the longest measured run, selecting the correct table, determining connected demand, and using the chosen length consistently when sizing sections of the system.

Hydronics, ducts, and oil burners each account for six questions. Hydronic preparation should include boilers, pumps, circulators, expansion control, piping arrangements, heat emitters, heat exchangers, valves, controls, system operation, and maintenance.

Duct preparation should include airflow, friction rate, velocity, sizing, materials, fittings, reinforcement, sealing, supports, fabrication, and air-distribution performance. Oil-burner preparation should cover fuel delivery, tanks, piping, burner components, ignition, combustion, draft, controls, venting, adjustment, testing, service, and troubleshooting.

Refrigerants and refrigeration account for five questions. Candidates should understand the refrigeration cycle, refrigerants, compressors, condensers, evaporators, metering devices, pressure-temperature relationships, operating conditions, maintenance, and troubleshooting.

Heating and cooling principles, controls, furnaces and heaters, and safety each account for four questions. Candidates should also prepare for heat pumps, chimneys, flues, vents, boilers, combustion air, chillers, ventilation, machinery rooms, insulation, testing, balancing, hangers, supports, sound, vibration, and seismic control.

With 180 minutes available for 70 questions, candidates have an average of approximately two minutes and thirty-four seconds per question. This includes reading the question, identifying the subject, selecting the correct reference, locating the supporting information, and choosing an answer.

Open Book Test

The Connecticut S-2 Unlimited Heating, Piping and Cooling Journeyperson examination is an open-book test. Candidates may bring approved references and permitted tools into the examination center under the applicable testing rules.

The approved S-2 exam-room materials included in this package are the International Mechanical Code; NFPA 54; NFPA 31; OSHA 29 CFR Part 1926; Modern Refrigeration and Air Conditioning; the Ductulator; HVAC Duct Construction Standards; NFPA 58; and NFPA 56.

Modern Hydronic Heating, Residential Oil Burners, and Steam Plant Operation are supplemental study books. They provide additional technical instruction during preparation but are not included in the list of books allowed inside the S-2 examination room.

Approved references may be highlighted, underlined, annotated, and indexed before the examination. Permanent tabs may be used to identify chapters, definitions, tables, fuel-gas provisions, oil-burning requirements, refrigeration subjects, ductwork topics, hydronic material, safety rules, and boiler information.

Temporary tabs, removable notes, loose papers, and inserted pages are not permitted. Candidates may not write in approved references during the examination, and examination questions or answers may not be recorded inside the books.

This standard package is not identified as highlighted or tabbed. Candidates who intend to add permitted highlighting, annotations, or permanent tabs should complete that preparation before test day and follow the applicable testing rules.

A mechanical installation, equipment, machinery-room, ventilation, combustion-air, duct, chimney, vent, boiler, or piping question may lead to the International Mechanical Code. Natural-gas piping, sizing, appliance, regulator, testing, combustion-air, and venting questions may require NFPA 54.

Oil-burning equipment, fuel-oil tanks, piping, controls, combustion air, and venting questions may require NFPA 31. LP gas container, storage, regulator, piping, equipment, and separation questions may lead to NFPA 58.

Questions involving cleaning or purging flammable gas piping may require NFPA 56. Construction-safety questions may require OSHA 29 CFR Part 1926. Technical questions involving refrigeration, heating, cooling, hydronics, equipment, controls, maintenance, and troubleshooting may be supported by Modern Refrigeration and Air Conditioning.

Duct-construction questions may require HVAC Duct Construction Standards, while duct-sizing questions may involve the Ductulator. Candidates should determine whether a question concerns airflow calculations or physical construction before choosing a source.

Licensing Steps

1. Review the S-2 license scope. Confirm that the Connecticut Unlimited Heating, Piping and Cooling Journeyperson classification matches the work you intend to perform.
2. Complete the qualifying pathway. Complete a registered apprenticeship program or an equivalent experience-and-training pathway accepted by Connecticut.
3. Gather supporting records. Prepare apprenticeship records, classroom documentation, employment verification, and other materials required for the applicable application route.
4. Complete the journeyperson application. Submit the applicable S-2 application, supporting documentation, and required state fees to the Connecticut Department of Consumer Protection.
5. Receive examination eligibility. Connecticut reviews the applicant’s qualifications and determines whether the candidate may proceed to testing.
6. Prepare for the S-2 examination. Study the approved references and use the supplemental books to reinforce hydronic, oil-burner, boiler, and steam-system knowledge.
7. Practice calculations. Work with gas-pipe sizing, duct sizing, airflow, velocity, friction rate, connected demand, and related technical problems.
8. Practice open-book navigation. Learn which source applies to each subject and locate provisions, definitions, diagrams, and tables under timed conditions.
9. Schedule the examination. Follow the testing provider’s registration and scheduling procedures after receiving eligibility.
10. Complete the S-2 examination. Take the 70-question examination within the three-hour testing period.
11. Complete license-issuance requirements. Submit any remaining examination results, documents, or licensing fees required by Connecticut.

Passing the examination does not automatically issue the S-2 license. Applicants must complete Connecticut’s training, application, examination, documentation, and license-issuance requirements.

State Requirements

The Connecticut S-2 credential is an Unlimited Heating, Piping and Cooling Journeyperson license. The holder may perform heating, piping, and cooling work within the authority established for the classification.

The S-2 classification is broader than Connecticut’s limited heating, cooling, refrigeration, fuel-gas, and oil-burner journeyperson licenses. It covers an extensive range of heating, air-conditioning, refrigeration, hydronic, boiler, oil, gas, ventilation, piping, and related system work.

The S-2 credential does not automatically replace occupational licenses required for unrelated electrical, plumbing, fire-protection, or other separately regulated work. License holders must remain within the legally authorized scope of the credential.

The S-2 license is a journeyperson credential and does not provide independent contracting authority. The holder performs authorized work while employed by or under the supervision of an appropriately licensed contractor.

Applicants generally qualify by completing the applicable registered apprenticeship program or an accepted equivalent experience-and-training pathway. Supporting records may be required to document classroom education, supervised employment, apprenticeship completion, or equivalent qualifications.

Applicants with experience, education, or occupational credentials obtained outside Connecticut should follow the applicable state review process. Connecticut determines whether submitted qualifications satisfy the requirements for examination eligibility and license issuance.

Candidates should review the S-2 classification before applying. Connecticut offers several unlimited and limited heating, cooling, refrigeration, fuel, piping, and oil-related licenses, and the selected credential should match the work the applicant plans to perform.

Reference Books

• International Mechanical Code, 2021
  This approved exam-room code covers mechanical equipment, refrigeration systems, machinery rooms, ventilation, combustion air, ducts, chimneys, vents, boilers, piping, and related installation requirements.
• NFPA 54 - National Fuel Gas Code Handbook, 2012
  This approved reference covers natural-gas piping, sizing, pressure regulation, appliance installation, combustion air, venting, testing, and related safety provisions.
• NFPA 31: Standard for the Installation of Oil-Burning Equipment, 2011
  This approved standard covers oil-burning equipment, fuel-oil tanks, piping, controls, combustion air, venting, installation, and safety requirements.
• Code of Federal Regulations - 29 CFR Part 1926 (OSHA)
  This approved safety reference addresses construction hazards, personal protective equipment, fall protection, ladders, scaffolds, excavation, electrical safety, and jobsite responsibilities.
• Modern Refrigeration and Air Conditioning, 22nd Edition
  This approved technical reference supports refrigeration, air conditioning, heating, hydronics, controls, equipment operation, maintenance, testing, and troubleshooting.
• Ductulator
  This approved tool supports duct sizing, airflow, velocity, friction-rate relationships, and air-distribution calculations.
• HVAC Duct Construction Standards, Metal and Flexible, 2005, 3rd Edition
  This approved reference covers duct materials, fabrication, reinforcement, fittings, sealing, supports, and construction requirements.
• NFPA 58 - Liquefied Petroleum Gas Code, 2014
  This approved standard covers LP gas containers, storage, regulators, piping, equipment, installation, separation requirements, and related safety provisions.
• NFPA 56: Standard for Fire and Explosion Prevention During Cleaning and Purging of Flammable Gas Piping, 2023
  This approved standard addresses planning, cleaning, purging, monitoring, ignition-source control, and fire and explosion prevention for flammable gas piping systems.
• Modern Hydronic Heating for Residential and Light Commercial Buildings, John Siegenthaler, P.E., 2022
  This supplemental study book provides detailed instruction involving boilers, circulators, heat emitters, radiant systems, expansion control, hydraulic separation, piping arrangements, and modern hydronic design.
• Residential Oil Burners, 3rd Edition
  This supplemental study book covers residential oil-burner components, fuel delivery, combustion, ignition, controls, draft, adjustment, testing, maintenance, and troubleshooting.
• Steam Plant Operation, 10th Edition, 2017
  This supplemental technical reference covers steam generation, boilers, plant equipment, water treatment, controls, operation, maintenance, efficiency, safety, and troubleshooting.

Exam Room Approved Books

The following materials from this package are approved for applicable use during the Connecticut S-2 open-book examination:

• International Mechanical Code, 2021
  Use this code for equipment, refrigeration systems, ventilation, combustion air, ducts, chimneys, vents, boilers, piping, and mechanical installation requirements.
• NFPA 54 - National Fuel Gas Code Handbook, 2012
  Use this reference for natural-gas piping, sizing, appliances, regulators, combustion air, venting, and testing.
• NFPA 31: Standard for the Installation of Oil-Burning Equipment, 2011
  Use this standard for oil-burning equipment, fuel-oil tanks, piping, controls, combustion air, and venting.
• Code of Federal Regulations - 29 CFR Part 1926 (OSHA)
  Use this reference for construction-safety questions and jobsite responsibilities.
• Modern Refrigeration and Air Conditioning, 22nd Edition
  Use this reference for refrigeration, heating, cooling, hydronics, controls, equipment, maintenance, and troubleshooting.
• Ductulator
  Use this tool for duct sizing, airflow, velocity, and friction-rate calculations.
• HVAC Duct Construction Standards, Metal and Flexible, 2005, 3rd Edition
  Use this reference for duct fabrication, materials, reinforcement, fittings, sealing, and supports.
• NFPA 58 - Liquefied Petroleum Gas Code, 2014
  Use this standard for LP gas containers, regulators, storage, piping, equipment, installation, and safety.
• NFPA 56: Standard for Fire and Explosion Prevention During Cleaning and Purging of Flammable Gas Piping, 2023
  Use this standard for cleaning and purging procedures involving flammable gas piping systems.

Modern Hydronic Heating, Residential Oil Burners, and Steam Plant Operation are included as supplemental study resources and are not listed as books allowed inside the S-2 examination room.

Test Information and Study Materials

A productive S-2 study plan should begin with fuel-gas systems, hydronics, ducts, oil burners, and refrigeration because these subjects represent a substantial portion of the examination.

Use NFPA 54 to study natural-gas piping, pressure, sizing, regulators, appliances, testing, combustion air, and venting. Practice the longest-length sizing method until the process can be completed accurately under timed conditions.

Use NFPA 56 to review planning and safety procedures for cleaning and purging flammable gas piping. Study monitoring, discharge locations, communication, ignition-source control, and fire and explosion prevention.

Use NFPA 31 together with Residential Oil Burners to study oil-burning equipment, tanks, fuel delivery, piping, controls, combustion, draft, venting, adjustment, testing, service, and troubleshooting.

Use Modern Hydronic Heating and Steam Plant Operation to deepen your understanding of boilers, steam generation, circulation, piping arrangements, expansion control, pumps, heat emitters, water treatment, controls, maintenance, and system performance.

Use the Ductulator and HVAC Duct Construction Standards together. The Ductulator supports airflow and sizing calculations, while the construction standard addresses materials, fabrication, fittings, reinforcement, sealing, and supports.

Timed reference practice should include selecting the correct source before beginning the search. Candidates should use indexes, tables of contents, chapter headings, definitions, diagrams, and technical tables to locate the supporting information.

How 1 Exam Prep Helps You Reach Your Goal

1 Exam Prep helps Connecticut S-2 candidates prepare with an organized combination of approved exam-room references and supplemental technical books. The package supports study across fuel gas, hydronics, oil burners, refrigeration, boilers, steam systems, ducts, controls, safety, ventilation, and mechanical requirements.

Trade-focused review helps candidates connect each examination category with the correct reference. Mechanical questions can be researched in the International Mechanical Code, natural-gas questions in NFPA 54, oil-burning questions in NFPA 31, and LP gas questions in NFPA 58.

The supplemental books provide additional explanations for hydronic systems, oil burners, boilers, steam equipment, circulation, combustion, controls, maintenance, and troubleshooting. This technical foundation can make formal code and standard requirements easier to understand.

Practice-oriented preparation helps candidates work through gas-pipe sizing, duct-sizing calculations, technical tables, diagrams, and system-operation questions. Researching missed questions strengthens both trade knowledge and reference-navigation ability.

Reference familiarity is especially important for an examination that uses several different sources. Candidates can practice identifying the subject, choosing the correct book, locating useful index terms, and reading the complete supporting section within the available time.

No exam book package can guarantee examination eligibility, a passing score, application approval, or license issuance. Candidates remain responsible for meeting Connecticut’s qualification requirements, preparing thoroughly, passing the examination, and completing the licensing process.

FAQ Section

What is included in this S-2 Exam Book Package?

The package includes nine approved exam-room references and tools plus three supplemental study books covering hydronic heating, residential oil burners, and steam-plant operation.

Is the Connecticut S-2 examination open book?

Yes. Candidates may bring approved references and permitted tools into the examination center under the applicable testing rules.

How many questions are on the S-2 examination?

The S-2 examination contains 70 questions. Candidates have three hours to complete the test and must earn a minimum score of 70 percent.

What is the largest S-2 examination category?

Fuel-gas systems are the largest category with 10 questions. Hydronics, ducts, and oil burners each account for six questions.

Are all twelve books allowed into the examination?

No. Modern Hydronic Heating, Residential Oil Burners, and Steam Plant Operation are supplemental study books and are not listed as approved S-2 exam-room references.

Is NFPA 56 included?

Yes. NFPA 56, 2023 is included for preparation involving cleaning and purging flammable gas piping.

Is a Ductulator included?

Yes. A Ductulator is included for duct-sizing, airflow, velocity, and friction-rate preparation.

Does the package include hydronic and steam study books?

Yes. Modern Hydronic Heating and Steam Plant Operation are included as supplemental technical study resources.

Are the books highlighted and tabbed?

No highlighting or tabbing service is identified as part of this standard S-2 Exam Book Package.

Does this package include online course access?

No. This product is a printed exam book package and does not include online course access.

Does the S-2 license allow independent contracting?

No. The S-2 credential is a journeyperson license. The holder performs authorized work while employed by or under the supervision of an appropriately licensed contractor.

Does purchasing this package guarantee an S-2 license?

No. Applicants must meet Connecticut’s qualification requirements, receive examination eligibility, pass the examination, complete the licensing process, and receive state approval.