- The C-1 trade exam has 120 scored questions, a five-hour limit, and requires 84 correct (70%) to pass.
- Drain, Waste, and Vents carries the heaviest weight at 10 items; Gas Systems, Water Supply, Traps and Interceptors, and Isometric Analysis/Plumbing Math each...
- Only five references are allowed in the exam room: UPC 2018, UMC 2018, NFPA 54 (2012), NFPA 58 (2014), and NFPA 13 (2019).
- PSI charges $95 for one exam portion or $140 when pairing the trade exam with the CMS business-and-law exam.
Exam Format Snapshot
This cheat sheet condenses the operational facts of the Nevada Plumbing and Heating Contractor (C-1) Trade Exam into one scannable reference. It covers the full C-1 exam administered through PSI Services LLC on behalf of the Nevada State Contractors Board - not the C-1d plumbing-only exam, which follows a different scope entirely. If you need the deep-dive version of any section below, the NV-C1 Study Guide 2026 and NV-C1 Exam Domains 2026 guide walk through each topic in more depth.
The exam is computer-administered and open-book, meaning you bring your own approved references rather than relying on memorized code text. Before you can even schedule a seat with PSI, the Nevada State Contractors Board must approve your application - scheduling is not available until that approval lands. For a candid look at where this exam sits on the difficulty spectrum compared to other trade tests, see How Hard Is the NV-C1 Exam?
Fees and Registration Mechanics
Registration mechanics matter as much as content knowledge because a missed fee or paperwork step can delay your seat date by weeks. Here is the fee structure exactly as PSI and the Board apply it:
| Item | Amount |
|---|---|
| PSI exam fee, one portion (trade exam only) | $95 |
| PSI exam fee, two portions (trade exam + CMS) | $140 |
| Board application fee | $300 |
| Initial two-year license | $600 |
| Biennial license renewal | $600 |
Note that the Contractor Management Survey (CMS) is a separate examination with its own 75% passing standard covering business and law content. It is billed together with the trade exam only when you choose to test for both in one sitting; its content should never be blended into your C-1 trade-domain study sessions. For a full cost breakdown across the entire licensing process, see NV-C1 Certification Cost 2026.
Key Takeaway
Pay the Board application fee and secure approval first - PSI scheduling only opens after the Board clears your application, so treat that step as the true start of your countdown, not the day you register with PSI.
Domain Weighting Cheat Sheet
The blueprint below reflects the PSI bulletin updated March 25, 2026, and lists the official item allocation across all 23 content domains. Use these counts to decide where your study hours should actually go - proportional weighting beats generic outlines every time.
| # | Domain | Items |
|---|---|---|
| 1 | Boilers | 4 |
| 2 | Gas Systems | 8 |
| 3 | Cleanouts | 4 |
| 4 | Fixtures and Equipment | 4 |
| 5 | Hydronics | 3 |
| 6 | Water Heaters/Venting | 6 |
| 7 | Piping, Valves, and Controls | 3 |
| 8 | Sheet Metal | 3 |
| 9 | Water Supply | 8 |
| 10 | Hangers and Supports | 5 |
| 11 | Drain, Waste, and Vents | 10 |
| 12 | Backflow | 4 |
| 13 | Traps and Interceptors | 8 |
| 14 | Isometric Analysis/Plumbing Mathematics | 8 |
| 15 | Safety | 5 |
| 16 | Joints and Connections | 4 |
| 17 | Solar | 4 |
| 18 | General Plumbing Requirements | 7 |
| 19 | Fire Sprinklers | 5 |
| 20 | Storm Drainage | 5 |
| 21 | Industrial Piping | 3 |
| 22 | Breathing Systems for Firefighters | 3 |
| 23 | Chilled Water Piping | 6 |
Total: 120 scored items. Domains with 3-4 items each still add up quickly - Boilers, Cleanouts, Fixtures and Equipment, Hydronics, Piping/Valves/Controls, Sheet Metal, Backflow, Joints and Connections, Solar, Industrial Piping, and Breathing Systems for Firefighters together cover more than a third of the exam even though none stands out individually.
High-Value Domains to Master
Four domains tie for the second-highest weight at 8 items each, and one domain sits alone at the top with 10. Together these five domains account for 42 of the 120 scored questions - over a third of your score.
Drain, Waste, and Vents (10 items)
The single largest domain on the exam. Expect sizing questions, venting configurations, slope requirements, and code-referenced scenarios pulled from UPC 2018.
- Practice fixture unit calculations and vent sizing tables until they're automatic
- Know the difference between common venting arrangements and when each applies
Gas Systems (8 items)
Gas piping sizing, appliance venting, and shutoff requirements draw heavily on NFPA 54 (2012). Candidates who skip this reference tend to lose points here.
- Practice reading NFPA 54 sizing tables under time pressure
- Review appliance clearance and venting rules alongside boiler and water heater content
Water Supply (8 items)
Covers distribution sizing, pressure calculations, and material selection under UPC 2018. This domain overlaps conceptually with Backflow and Hangers and Supports, so studying them together saves time.
- Master pipe sizing methodology, not just memorized table values
- Understand water hammer and pressure-loss scenarios
Traps and Interceptors (8 items)
Trap sealing, interceptor sizing, and grease/oil separator requirements are common scenario-question territory. These questions often combine code citation with a simple math step.
- Practice trap-arm distance limits and interceptor placement rules
- Cross-check interceptor sizing against fixture load
Isometric Analysis/Plumbing Mathematics (8 items)
This domain tests your ability to read an isometric drawing and perform the associated calculations - offset angles, pipe length, and slope math. It rewards practice with actual drawings, not just formulas.
- Work through offset and rise/run problems using your approved calculator
- Practice translating an isometric sketch into a fixture-unit or slope calculation
A full breakdown of every domain, including the smaller-weighted ones, is available in the NV-C1 Exam Domains 2026 Complete Guide. If you're still deciding how much preparation time this exam warrants overall, the difficulty guide and pass rate breakdown put the workload in context.
Approved References and Materials Rules
Because the exam is open-book, knowing exactly what you can and cannot bring is as important as knowing the content. Only five texts are admitted into the exam room:
- UPC 2018 (Uniform Plumbing Code)
- UMC 2018 (Uniform Mechanical Code)
- NFPA 54 (2012) - National Fuel Gas Code
- NFPA 58 (2014) - Liquefied Petroleum Gas Code
- NFPA 13 (2019) - Standard for the Installation of Sprinkler Systems
The bulletin also lists study references you may use while preparing that cannot be brought into the testing room - do not confuse a preparation resource with an admitted reference. If a book isn't on the five-title list above, leave it at home. A full rundown of what's admissible and what to buy for practice appears in a companion piece on NV-C1 Exam Prep's resource pages.
Eligibility and Licensing Snapshot
Before you sit for the exam, the Board needs to see qualifying experience. The standard path requires four full years of qualifying journeyman, supervisory, or contractor experience within the preceding 15 years. Board-approved education can substitute for up to three of those four years, but it cannot replace all of them.
- Financial, bond, and applicable insurance requirements apply alongside the experience test
- Board application and approval must precede exam scheduling with PSI
- Initial licensure runs for two years, with renewal due biennially at $600 and ongoing bond/insurance compliance
For the full eligibility checklist and documentation tips, see NV-C1 Requirements 2026. If you're weighing whether the licensing investment pays off against the work available to C-1-licensed contractors in Nevada, Is the NV-C1 Certification Worth It? covers that analysis, and the salary guide looks at earnings potential for licensed plumbing and heating contractors.
Retake and Renewal Rules
Passing requires exactly 84 correct answers out of 120 - there's no partial credit for being close. If you fall short:
- You must wait two weeks before scheduling another attempt
- Three failed attempts void the application entirely, requiring you to start the Board application process over
Key Takeaway
Treat every attempt as one of only three chances tied to a single application. Use the mandatory two-week wait to target the exact domains that cost you points rather than re-reading everything from scratch. For the exact math behind the 70% threshold, see NV-C1 Passing Score 2026.
Once licensed, renewal happens every two years at $600, contingent on maintaining bond and applicable insurance coverage. Missing renewal deadlines creates the same kind of paperwork delay as missing Board approval before your first exam - plan renewal dates the same way you planned your original test date. See NV-C1 Exam Dates 2026 for scheduling windows and deadline planning.
Final Review Week Plan
In the final week before your seat date, shift from broad studying to targeted review anchored to the domain weights above. This isn't a generic study calendar - it's built around where the 120 questions actually live.
Heaviest Domains First
- Drill Drain, Waste, and Vents (10 items) using UPC 2018 tables
- Review Gas Systems (8 items) against NFPA 54 (2012)
Remaining 8-Item Domains
- Work Water Supply and Traps and Interceptors problems back-to-back since both draw on UPC 2018
- Practice Isometric Analysis/Plumbing Mathematics using your approved calculator only
Mid-Weight Domains
- Cover General Plumbing Requirements (7), Water Heaters/Venting (6), Chilled Water Piping (6), and Hangers and Supports, Safety, Fire Sprinklers, and Storm Drainage (5 each)
- Cross-check NFPA 13 (2019) content against Fire Sprinklers questions
Light-Weight Domains and Logistics
- Quickly review the 3-4 item domains: Boilers, Cleanouts, Fixtures and Equipment, Hydronics, Piping/Valves/Controls, Sheet Metal, Backflow, Joints and Connections, Solar, Industrial Piping, Breathing Systems for Firefighters
- Confirm your five approved references have permanent tabs placed and your calculator meets the nonprogrammable requirement
This kind of proportional review week works best as a finishing pass after a full study cycle - for the complete multi-week preparation plan, read the NV-C1 Study Guide 2026. When you're ready to test your recall under timed conditions, a full-length simulation at NV-C1 Exam Prep is the fastest way to find remaining gaps before test day.
Frequently Asked Questions
The exam has 120 scored questions with a five-hour time limit. PSI may add 1-10 unscored experimental questions, which count against your available time even though they don't affect your score.
You need 84 correct answers out of 120, which equals 70%. This is a fixed threshold - there is no curve or partial credit adjustment.
You may bring only the five approved references: UPC 2018, UMC 2018, NFPA 54 (2012), NFPA 58 (2014), and NFPA 13 (2019). Advance highlighting, underlining, and permanent tabs are allowed, but handwritten notes, loose papers, and temporary tabs are prohibited.
You must wait two weeks before scheduling a retake. If you fail three times, your application is voided and you must restart the Board application process.
PSI charges $95 to sit for the trade exam alone, or $140 if you pair it with the CMS business-and-law exam in the same sitting. This is separate from the Board's $300 application fee and the $600 initial license fee.