Arizona Plumbing Commercial Contractor (C-37) Exam - Online Exam Prep

The Arizona Plumbing Commercial Contractor (C-37) Exam - Online Exam Prep course is designed for candidates preparing for the Arizona commercial plumbing contractor trade exam. This online course helps students study the major knowledge areas connected to drainage, waste and vents, indirect waste, water supply systems, backflow prevention, roof drains, storm drainage systems, plumbing fixtures, water heaters, accessibility, specialty plumbing, interceptors, traps, fuel gas, sewer systems, hydronics, fire sprinklers, excavation, pipe trade mathematics, OSHA construction safety, and Arizona underground utility awareness.

The Arizona C-37 Plumbing classification focuses on commercial plumbing work. Candidates preparing for this exam should understand plumbing systems used in commercial buildings and on private property, including water supply, sanitary drainage, venting, gas piping, hydronic heating, storm drainage, fire sprinkler concepts, excavation practices, and pipe trade calculations. Plumbing work affects sanitation, safety, water quality, drainage performance, fuel gas safety, and building function, so exam preparation should include both code-based requirements and practical pipe trade knowledge.

This online exam prep course gives candidates a structured way to prepare for the Arizona C-37 Plumbing exam without trying to organize the entire study process alone. The exam is open book, which means students should prepare in two important ways: by learning the plumbing trade material and by becoming familiar with the approved references used during testing. Strong preparation includes reviewing the official content outline, studying key code sections, learning how the books are organized, and practicing how to locate information efficiently during a timed exam.

The Arizona Plumbing Commercial Contractor (C-37) Exam - Online Exam Prep course is a strong fit for qualifying parties, commercial plumbing contractors, plumbers, pipefitters, hydronic heating professionals, fire sprinkler professionals, project managers, supervisors, business owners, and experienced tradespeople preparing for Arizona contractor licensing. The course helps students review the exam subjects, connect those subjects to the listed references, and approach the test with a more organized preparation routine.

Commercial plumbing exam preparation requires attention to both technical detail and speed. Candidates may need to answer questions about fixture requirements, pipe sizing, venting, drainage layout, water distribution, backflow devices, fuel gas systems, hydronic heating, sprinkler systems, excavation safety, pipe materials, fittings, and jobsite hazards. This course helps candidates study those areas in a focused, exam-oriented format that supports open book test readiness.

Exam Details

The Arizona C-37 Plumbing commercial contractor exam is administered through PSI for the Arizona Registrar of Contractors. The trade exam contains 100 questions, and candidates are allowed 240 minutes to complete the test. The minimum passing score is 70%.

The Arizona C-37 Plumbing exam uses the same trade examination content as the residential R-37 Plumbing and residential / commercial CR-37 Plumbing classifications. Candidates should select the license classification that matches the work they plan to perform and follow the Arizona Registrar of Contractors licensing process for that classification.

The content outline includes Drainage Waste and Vents, Indirect Waste, Water Supply Systems, Backflow Prevention, Roof Drains and Storm Drainage Systems, Plumbing Fixtures including water heaters and accessibility, General Knowledge, Specialty Plumbing, Interceptors, and Traps, Fuel Gas, Septic and Sewer, Hydronics, Fire Sprinklers, and Excavation.

Drainage Waste and Vents includes 15 items. Indirect Waste includes 4 items. Water Supply Systems includes 12 items. Backflow Prevention includes 5 items. Roof Drains and Storm Drainage Systems includes 5 items. Plumbing Fixtures, including water heaters and accessibility, includes 6 items. General Knowledge includes 8 items. Specialty Plumbing, Interceptors, and Traps includes 5 items. Fuel Gas includes 11 items. Septic and Sewer includes 11 items. Hydronics includes 6 items. Fire Sprinklers includes 6 items. Excavation includes 6 items.

Drainage Waste and Vents is the largest section of the exam, so candidates should give this topic significant study time. This area may include traps, vents, fixture drains, branch drains, building drains, building sewers, cleanouts, slope, pipe sizing, fittings, vent connections, and sanitary drainage layout. A strong understanding of drainage and venting is essential because these systems protect sanitation, odor control, and proper fixture operation.

Water Supply Systems, Fuel Gas, and Septic and Sewer are also major exam areas. Water supply questions may involve distribution piping, pressure, valves, water heaters, materials, sizing concepts, protection from contamination, and safe delivery of potable water. Fuel gas questions may involve gas pipe sizing, appliance connections, vents, combustion air awareness, fuel gas code requirements, pressure testing, and safety. Septic and sewer questions may involve sewer connections, wastewater movement, onsite system awareness, and related code or rule requirements.

The remaining sections support a complete plumbing exam preparation plan. Backflow prevention, storm drainage, hydronics, fire sprinklers, excavation, fixtures, specialty plumbing, and general knowledge can all affect the final score. Because the exam includes 100 questions across many subject areas, candidates should study broadly and avoid focusing on only one code book or one part of plumbing work.

Open Book Test

The Arizona C-37 Plumbing exam is an open book test. Candidates are responsible for bringing their own approved references to the examination center. Approved reference materials may be highlighted, underlined, annotated, and indexed before the exam session begins. Candidates may not write, highlight, underline, or index inside the references during the examination session.

Reference books may be tabbed or indexed with permanent tabs only. Permanent tabs are tabs that would tear the page if removed. Temporary tabs, removable sticky notes, and other removable tabs are not allowed and must be removed before the exam begins. Candidates may not bring loose papers or attached papers with the approved references.

If a candidate uses a permitted reference downloaded from the internet, the material must be bound before being brought into the testing center. A bound reference may be spiral bound or hole-punched and placed in a binder when allowed by the exam instructions. Candidates may use a silent, nonprinting, non-programmable calculator in the examination center.

The exam-room-approved references include Code of Federal Regulations – 29 CFR Part 1926 (OSHA), International Fuel Gas Code, International Mechanical Code, International Plumbing Code, NFPA 13, NFPA 13D, and NFPA 13R. The additional pipe trade, hydronic, boiler, mathematics, and Arizona 811 references are study materials and are not allowed in the examination center.

Open book testing rewards candidates who study with the references before test day. Simply bringing the books into the testing center is not enough. Candidates should know where IPC drainage and water supply provisions are located, where IFGC fuel gas requirements are found, where IMC hydronic and mechanical topics appear, where NFPA sprinkler provisions are organized, and where OSHA excavation and construction safety rules can be found. The study-only references help candidates build trade knowledge before the exam, even though they are not brought into the testing room.

Licensing Steps

Arizona contractor licensing is handled by the Arizona Registrar of Contractors. A candidate pursuing the Arizona Plumbing Commercial Contractor (C-37) license should begin by confirming that the C-37 commercial classification matches the type of plumbing work the business intends to perform. The qualifying party must complete the examination requirements connected to the license classification.

Many Arizona contractor license applicants must complete the applicable trade exam and the Arizona Statutes and Rules Training Course and Exam. The trade exam measures plumbing and construction knowledge for the license classification, while the statutes and rules requirement covers Arizona contractor law and regulatory responsibilities. Candidates should follow the Arizona Registrar of Contractors application process for the business structure, qualifying party, experience, bonding, and supporting documents that apply to the license being pursued.

A practical preparation path begins with identifying the correct classification, reviewing the official exam content outline, gathering the approved references, and setting a realistic study schedule. After preparation, the candidate schedules the trade exam through PSI and follows testing center rules for identification, reference materials, calculators, personal items, and exam-room conduct.

After the required examination steps are completed, the applicant continues through the Arizona Registrar of Contractors licensing process. This may include submitting the license application, identifying the qualifying party, providing required business information, meeting bonding requirements, and satisfying other state requirements connected to the applicant and classification.

State Requirements

The Arizona C-37 Plumbing classification is the commercial plumbing contractor classification. This classification is intended for contractors who perform plumbing work in commercial settings within the allowed license scope.

The plumbing scope includes installation, alteration, and repair of plumbing performed within property lines and not on public easements or rights-of-way, except as permitted by the classification. It includes piping, fixtures, and appliances related to water supply; pressure vessels and tanks; venting and sanitary drainage systems; septic tanks and leaching lines; roof leaders; lawn sprinklers; water conditioning equipment; and piping and equipment for swimming pools.

The scope also includes piping, fixtures, appliances, and pressure vessels for manufactured and natural gases, compressed air and vacuum systems, petroleum, fuel oil, non-potable liquids, hot water heating and hot water supply systems within listed pressure and temperature limitations, steam heating and steam supply systems within listed operating pressure limitations, gas or oil fired space heaters and furnaces excluding duct work, water cooling system piping excluding refrigerant piping and equipment, and testing and balancing of hydronic systems.

Sewer, gas, and water lines, and connections from a structure to the nearest point of public supply or disposal, may cross public or private easements or be installed within private easements under the scope limitations. Pipe installed across public property may not be increased in size or make another connection between the point of exit from private property and the point of connection at public supply or disposal. These lines may not be installed parallel to main lines in public easements or rights-of-way.

Arizona issues separate contractor license classifications for commercial work, residential work, and dual residential/commercial work. The C-37 classification is the commercial plumbing contractor classification. Applicants should make sure the classification fits the type of contracting work they plan to offer before moving forward with exam preparation and licensing paperwork.

Reference Books

• Code of Federal Regulations – 29 CFR Part 1926 (OSHA)
  This construction safety reference supports study of OSHA standards used on plumbing jobsites, including excavation safety, trenching, ladders, scaffolds, personal protective equipment, tools, material handling, and general construction hazard recognition.
• International Fuel Gas Code (IFGC), 2018
  This code reference supports study of fuel gas piping, gas pipe sizing, appliance connections, combustion air, venting, shutoff valves, pressure testing, installation requirements, and fuel gas safety.
• International Mechanical Code (IMC), 2018
  This code reference supports study of mechanical system provisions that may relate to plumbing and hydronic work, including hydronic heating, equipment, piping, ventilation concepts, and mechanical system coordination.
• International Plumbing Code (IPC), 2018
  This primary plumbing code reference supports study of drainage, waste and vents, water supply, fixtures, water heaters, traps, cleanouts, indirect waste, storm drainage, backflow prevention, pipe sizing, and plumbing system requirements.
• NFPA 13 – Installation of Sprinkler Systems, 2019
  This fire sprinkler reference supports study of sprinkler system installation, components, water supply, system layout, protection concepts, and commercial sprinkler system requirements.
• NFPA 13D – Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes, 2019
  This reference supports study of residential sprinkler systems for one- and two-family dwellings and manufactured homes, including system intent, components, water supply, and installation concepts.
• NFPA 13R – Sprinkler Systems for Residential Occupancies up to and Including Four Stories in Height, 2019
  This reference supports study of sprinkler systems for residential occupancies up to and including four stories in height, including protection concepts, system design awareness, and installation requirements.
• Mathematics for Plumbers and Pipefitters, 8th Edition
  This study reference supports review of plumbing and pipe trade calculations, measurements, fractions, decimals, percentages, area, volume, slopes, offsets, and practical field math.
• IPT’s Pipe Trades Handbook, Robert A. Lee, 2016
  This study reference supports review of pipe trade formulas, pipe data, fittings, layout, measurements, conversions, materials, and practical pipefitting information.
• Boiler Operator’s Guide, 5th Edition
  This study reference supports review of boiler operation, hot water heating, steam systems, safety controls, pressure concepts, equipment operation, and heating system awareness.
• Arizona 811 – Arizona Blue Stake Brochure
  This study reference supports review of underground utility notification, excavation awareness, safe digging practices, utility marking, and Arizona Blue Stake procedures.
• Modern Hydronic Heating for Residential and Light Commercial Buildings, 2022
  This study reference supports review of hydronic heating systems, boilers, pumps, circulators, piping, controls, heat transfer, zoning, and residential or light commercial hydronic design concepts.

Exam Room Approved Books

• Code of Federal Regulations – 29 CFR Part 1926 (OSHA)
  Approved for use in the exam room as the construction safety reference for OSHA-related exam topics.
• International Fuel Gas Code (IFGC), 2018
  Approved for use in the exam room as the fuel gas code reference for fuel gas piping, appliances, venting, combustion air, and safety requirements.
• International Mechanical Code (IMC), 2018
  Approved for use in the exam room as the mechanical code reference for hydronic and mechanical system topics connected to plumbing work.
• International Plumbing Code (IPC), 2018
  Approved for use in the exam room as the primary plumbing code reference for drainage, water supply, fixtures, traps, vents, storm drainage, and plumbing system requirements.
• NFPA 13 – Installation of Sprinkler Systems, 2019
  Approved for use in the exam room as the sprinkler system reference for NFPA 13 fire sprinkler topics.
• NFPA 13D – Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes, 2019
  Approved for use in the exam room as the residential sprinkler reference for one- and two-family dwelling and manufactured home sprinkler systems.
• NFPA 13R – Sprinkler Systems for Residential Occupancies up to and Including Four Stories in Height, 2019
  Approved for use in the exam room as the sprinkler reference for residential occupancies up to and including four stories in height.

Test Information and Study Materials

The Arizona C-37 Plumbing exam is broad, detailed, and timed. With 100 questions in 240 minutes, candidates should prepare to work efficiently across several code books and study references. A strong study routine includes reviewing the content outline, reading key code sections, learning book organization, building approved permanent tabs, practicing pipe trade math, and answering exam-style questions under timed conditions.

Drainage, Waste and Vents preparation should include fixture drains, traps, venting methods, cleanouts, fittings, pipe sizing, slope, building drains, building sewers, and sanitary drainage layout. Candidates should understand how vents protect trap seals and how drainage systems remove waste safely from the building.

Indirect Waste preparation should include air gaps, air breaks, indirect connections, receptors, food service equipment awareness, condensate discharge, and situations where plumbing systems must be protected from contamination. Commercial plumbing work often includes indirect waste connections, so candidates should know where these requirements appear in the plumbing code.

Water Supply Systems preparation should include potable water piping, pressure, valves, water heaters, fixture supply, materials, sizing concepts, and protection against contamination. Backflow Prevention should include backflow devices, cross-connection control, potable water protection, and situations where backflow protection is required.

Roof Drains and Storm Drainage Systems preparation should include roof drainage, storm piping, leaders, sizing awareness, secondary drainage concepts, cleanouts, and discharge requirements. Commercial projects may involve larger roof areas and storm systems, so candidates should understand how these topics fit within the IPC.

Plumbing Fixtures preparation should include fixture requirements, installation, water heaters, accessibility awareness, traps, clearances, fixture connections, and code-based installation practices. Specialty Plumbing, Interceptors, and Traps preparation should include grease interceptors, oil separators, trap requirements, special waste systems, and plumbing components used in commercial occupancies.

Fuel Gas preparation should include gas piping materials, pipe sizing, appliance connections, combustion air, venting, pressure testing, shutoff valves, regulators, and safe installation practices. Fuel gas questions require careful code navigation because gas systems involve serious safety risks.

Septic and Sewer preparation should include building sewers, sewer connections, wastewater flow, system location awareness, pipe materials, cleanouts, slope, and related installation practices. Candidates should understand how sewer work connects to plumbing systems and how underground conditions affect installation.

Hydronics preparation should include hot water heating, boilers, circulators, pumps, heat transfer, pipe sizing awareness, controls, zoning, pressure and temperature limits, and testing and balancing concepts. Fire Sprinklers preparation should include NFPA 13, NFPA 13D, and NFPA 13R organization, system components, water supply, occupancy-related sprinkler requirements, and installation concepts.

Excavation preparation should include trench safety, soil awareness, utility locating, Arizona 811 procedures, pipe bedding, backfill, compaction, and OSHA excavation requirements. Plumbing contractors often work below grade, so excavation knowledge supports both exam preparation and field safety.

OSHA Safety should be studied throughout the preparation process. Candidates should review excavation safety, ladders, scaffolds, personal protective equipment, material handling, tool safety, hazard communication, housekeeping, and jobsite hazard recognition. Plumbing work can involve trenches, confined areas, heavy pipe, fuel gas systems, hot water systems, elevated work, and active construction sites, so safety knowledge is essential for both the exam and field performance.

How 1 Exam Prep Helps You Reach Your Goal

1 Exam Prep helps students prepare for the Arizona Plumbing Commercial Contractor (C-37) Exam with organized study guidance, trade-focused review, code navigation support, and practice-oriented preparation. The course is designed to help candidates move through a large set of plumbing references with structure, so preparation feels more manageable and targeted.

For this exam, students need to understand drainage, waste and vents, indirect waste, water supply systems, backflow prevention, storm drainage, plumbing fixtures, fuel gas, sewer systems, hydronics, fire sprinklers, excavation, pipe trade math, and OSHA safety. 1 Exam Prep helps organize these areas into a clear preparation path that supports exam readiness.

Open book plumbing exams require more than owning the correct references. Students need to know how the books are arranged, how the exam topics connect to the references, and how to locate important information under time pressure. 1 Exam Prep supports this process through reference navigation guidance when applicable and an exam-focused study structure.

The course also helps students build confidence through repeated review and a more practical study routine. It does not replace hands-on plumbing experience, and it does not guarantee a passing score, license approval, or any specific outcome. It is built to help students prepare with better organization, stronger topic awareness, and more confidence as they approach the Arizona C-37 trade exam.

FAQ Section

What is the Arizona C-37 Plumbing contractor exam?

The Arizona C-37 Plumbing contractor exam is the trade exam for candidates pursuing the Arizona commercial plumbing contractor classification. It covers drainage, waste and vents, water supply, fuel gas, sewer systems, hydronics, fire sprinklers, excavation, and OSHA safety.

How many questions are on the Arizona C-37 Plumbing exam?

The exam contains 100 questions. Candidates are allowed 240 minutes to complete the test, and the minimum passing score is 70%.

Is the Arizona C-37 Plumbing exam open book?

Yes. The Arizona C-37 Plumbing exam is an open book test. Candidates may bring approved references into the testing center, but the books must follow exam-room rules for highlighting, annotations, indexing, permanent tabs, and permitted materials.

Which books are approved for the C-37 exam room?

The exam-room-approved references include OSHA, IFGC 2018, IMC 2018, IPC 2018, NFPA 13, NFPA 13D, and NFPA 13R.

Are all listed references allowed in the exam room?

No. Mathematics for Plumbers and Pipefitters, IPT’s Pipe Trades Handbook, Boiler Operator’s Guide, Arizona 811, and Modern Hydronic Heating are study references and are not allowed in the examination center.

What work is included in the Arizona C-37 classification?

The C-37 classification covers commercial plumbing work within the allowed license scope, including plumbing systems, water supply, drainage, fuel gas piping, hydronic systems, certain sewer, gas, and water connections, and related plumbing work.

What is the difference between C-37, R-37, and CR-37?

C-37 is the commercial plumbing classification, R-37 is the residential plumbing classification, and CR-37 is the dual residential / commercial plumbing classification that combines the allowed scopes of both.

What subjects should I study most for the C-37 exam?

Drainage, Waste and Vents is the largest section. Candidates should also study water supply systems, fuel gas, septic and sewer, hydronics, fire sprinklers, excavation, fixtures, backflow prevention, storm drainage, and OSHA safety.

Can I use temporary tabs in my books during the exam?

No. Temporary tabs are not allowed. Approved references may be tabbed or indexed with permanent tabs only, and removable notes or tabs must be removed before the exam begins.

Who should take this online exam prep course?

This course is intended for candidates preparing for the Arizona Plumbing Commercial Contractor (C-37) Exam, including qualifying parties, commercial plumbing contractors, pipefitters, supervisors, project managers, and business owners.

Does this course guarantee that I will pass the exam?

No. This course does not guarantee a passing score, license approval, or any specific exam outcome. It is designed to help students prepare through organized review, trade-focused study, code navigation, and open book practice.

Why is online exam prep helpful for this plumbing contractor exam?

Online exam prep helps students study with structure. It supports review of plumbing codes, fuel gas, sewer systems, hydronics, fire sprinklers, OSHA safety, and exam-style preparation so candidates can approach the timed open book test with better organization.