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Free Practice Questions for NV C-21F Chilled and Hot Water Systems

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Key Facts: NV C-21F Chilled and Hot Water Systems Exam

50 Q

Official Exam Questions

PSI Nevada Contractor CIB updated 3/25/2026

70%

Passing Score

PSI Nevada Contractor CIB updated 3/25/2026

2 hours

Time Allowed

PSI Nevada Contractor CIB updated 3/25/2026

USD 95

PSI Exam Fee (one portion)

PSI Nevada Contractor CIB updated 3/25/2026

Open Book

Book Policy

PSI Nevada Contractor CIB updated 3/25/2026

Nevada C-21F Chilled and Hot Water Systems Contractor Examination is the official NSCB/PSI open book exam: 50 questions, 70% (35 of 50 points), 2 hours, USD 95 (bulletin 270, updated 3/25/2026). Official delivery: English.

Sample NV C-21F Chilled and Hot Water Systems Practice Questions

Try these sample questions to review concepts for the NV C-21F Chilled and Hot Water Systems exam. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1Per NAC 624.380, Nevada C-21F chilled and hot water systems work includes installation of which of the following?
A.Boilers, chillers, coils, cooling towers, piping, pumps, storage tanks, and valves used to produce and transfer water for temperature control
B.Chilled-water piping only, with no authority to install or connect a chiller
C.Direct-expansion refrigerant piping inside a packaged rooftop unit only
D.Potable plumbing fixtures and sanitary drainage stacks
Explanation: NAC 624.380(3)(f) defines C-21F as the installation of boilers, chillers, coils, cooling towers, piping, pumps, storage tanks, valves, and other equipment used in the production and transfer of water for temperature control. That is broader than C-1I, which is chilled-water transfer piping only and expressly may not connect to a chiller.
2A closed hydronic chilled- or hot-water loop is best described as which of the following?
A.An open basin that continuously dumps circulating water to the sanitary sewer
B.A sealed, pressurized circuit that recirculates the same treated water through the plant, piping, and terminal coils
C.A once-through city-water line that discharges after a single pass through the coil
D.A potable-water distribution system serving lavatories and water closets
Explanation: UMC 2018 Chapter 12 hydronic heating and cooling systems are closed, pressurized loops. The same treated water is pumped through boilers or chillers, coils, and the piping network. An expansion tank absorbs thermal expansion. Makeup is only the small amount needed to replace leakage, not a continuous dump to drain.
3On a chemically treated closed chilled- or hot-water loop, which ferrous pipe is the ordinary above-ground commercial choice?
A.Unlisted fence tubing with no ASTM mark
B.Galvanized thin-wall EMT conduit
C.ASTM A53 Grade B Schedule 40 black steel, joined by welding, grooving, flanging, or threading as listed
D.Schedule 160 A106 steam pipe on every 1-inch branch
Explanation: UMC 2018 Table 1210.1 accepts listed steel pipe for hydronic service. ASTM A53 Grade B Schedule 40 black steel is the everyday commercial chilled- and hot-water product. A treated closed loop does not need a zinc coating, and galvanized flakes can foul valves and seals.
4Hydronic pipe, tubing, and fittings used on a C-21F chilled- or hot-water system must comply with which UMC 2018 source?
A.Any hardware-store hose that holds shop air
B.UMC Table 1210.1 listed materials rated for the system temperature, pressure, and fluid
C.Type DWV copper only, because hydronic water is not a pressure service
D.Unlisted irrigation tubing painted the system color
Explanation: UMC 2018 Section 1210.1 and Table 1210.1 are the allowed-materials list for hydronic pipe, tubing, and fittings. Steel, copper, stainless, listed PEX, PE-RT, PP, and other cited products are acceptable only when rated for the operating temperature, pressure, and fluid. Type DWV copper is a drainage product, not a hydronic pressure tube.
5Where copper hydronic tube is joined to carbon-steel pipe or a steel pump flange, UPC 2018 Sections 605.15 and 605.16 require which fitting?
A.A sanitary tee laid on its back
B.A no-hub shielded coupling listed only for cast-iron DWV
C.A brass cleanout plug
D.A dielectric union or other listed dielectric fitting
Explanation: UPC 2018 605.15 and 605.16 require a dielectric union or other listed dielectric fitting when copper or copper-alloy tube is joined to galvanized or carbon steel. Without isolation, galvanic current consumes the steel at the joint. The same rule applies at hydronic pumps, tanks, and steel mains.
6The extra duty of insulation on chilled-water pipe, compared with hot-water pipe, is to:
A.Provide a continuous vapor retarder so room-air moisture cannot condense on the cold pipe
B.Raise the circulating water to 180°F
C.Replace the need for pipe hangers
D.Allow the pipe to be tested with oxygen
Explanation: Chilled-water pipe sits below room dew point. If moist air reaches the cold metal, the line sweats, stains ceilings, and soaks the insulation. Closed-cell elastomeric or fiberglass with a sealed vapor-retarder jacket prevents that. Insulation does not replace hangers or change the test medium.
7Per UMC 2018 Section 1204.5, hydronic piping identification shall be placed at which interval?
A.Every 100 feet, and only in the mechanical room
B.Only at the building entrance
C.Every 20 feet, but not less than once per room, and visible from the floor
D.Identification is never required on closed loops
Explanation: UMC 2018 1204.5 requires the background color and required information every 20 feet (6096 mm), but not less than once per room, and visible from the floor level. That lets a mechanic or inspector identify chilled water, heating water, or heat-transfer fluid without tracing the line back to the plant.
8Per UMC 2018 Section 1205.3, what must be done to heating and cooling sources and system piping after installation?
A.Leave mill scale and cutting oil in the loop so inhibitors have something to react with
B.Flush with water or a cleaning solution compatible with all system components, following the equipment manufacturer's instructions
C.Blow the loop out with oxygen
D.Fill with untreated well water and place the chiller in service immediately
Explanation: UMC 2018 1205.3 requires heating and cooling sources, piping, and tubing to be flushed after installation with water or a cleaning solution. The solution must be compatible with all system components and used per the manufacturer's instructions. Debris left in the loop ruins pump seals, control valves, and chiller or boiler tubes.
9Which ASTM B88 copper water-tube type is the everyday above-ground hydronic choice on C-21F work?
A.Type DWV (yellow), because hydronic water is drainage
B.Type M only, because it is required underground
C.Type K only, because Type L is illegal indoors
D.Type L (blue mark), with Type K often reserved for burial and Type M the thinner above-ground wall
Explanation: ASTM B88 Type L (blue) is the common indoor chilled- and hot-water copper. Type K (green) is the heaviest wall and is the usual underground copper. Type M (red) is the thin above-ground water-tube wall. Type DWV is not a hydronic pressure product.
10UMC 2018 Section 1205.2 requires hydronic piping and components to be tested at:
A.Operating pressure for 5 minutes
B.10 psi air for 15 minutes on every plastic and steel system
C.Not less than 1.5 times the operating pressure, and not less than 100 psi, held at least 30 minutes with no perceptible drop
D.Any pressure the job-site compressor can reach
Explanation: UMC 2018 1205.2 is the Nevada hydronic test: 1.5 times operating pressure but not less than 100 psi, held not less than 30 minutes with no perceptible drop, in the presence of the Authority Having Jurisdiction. That is not the UPC fuel-gas test (10 psi / 15 minutes) and not a shop-air blow-down.

About the NV C-21F Chilled and Hot Water Systems Exam

The Nevada C-21F Chilled and Hot Water Systems Contractor Examination is the official Nevada State Contractors Board trade examination administered by PSI Services LLC. The official exam has 50 scored questions. Passing is 70% (35 of 50 points) in 2 hours. The examination is open book. Uniform Mechanical Code, 2018; Uniform Plumbing Code, 2018; and 29 CFR Part 1926 (allowed in center). PSI lists USD 95 for one examination portion and USD 140 if taken with CMS; otherwise USD 95 per trade exam (Candidate Information Bulletin 270, updated 3/25/2026). NSCB requires a separate CMS examination for most new applicants, plus a USD 300 application fee and a USD 600 biennial license fee. This English-language MCQ bank is a study aid, not an official PSI form. It does not replace required trade experience, board approval, fingerprints, bonding, or the official examination.

Exam sponsor: PSI Services LLC (for the Nevada State Contractors Board). The requirements and fees below concern the certification or admission exam, separate from our free practice resources.

Assessment

Open Book computer-based multiple-choice. Uniform Mechanical Code, 2018; Uniform Plumbing Code, 2018; and 29 CFR Part 1926 (allowed in center)

Time Limit

2 hours

Passing Score

70% (35 of 50 points)

Exam / Certification Fees

USD 95

Exam sponsor website

Fees, eligibility, and exam policies can change. Confirm them with the exam sponsor before applying or paying.

Our practice resources: topics covered

We aim to reflect publicly available exam outlines and topic information in our study resources. Coverage, format, and difficulty may differ from the actual exam, and we cannot guarantee that every detail is accurate or current. Confirm exam requirements, fees, and policies with the official exam sponsor.

30%

Piping

Piping (15 items)

20%

Water Cooling Equipment

Water Cooling Equipment (10 items)

20%

Water Heating Equipment

Water Heating Equipment (10 items)

16%

Valves and Controls

Valves and Controls (8 items)

14%

Safety

Safety (7 items)

Preparing for the NV C-21F Chilled and Hot Water Systems Exam

What You Need to Know

  • Passing score: 70% (35 of 50 points)
  • Assessment: Open Book computer-based multiple-choice. Uniform Mechanical Code, 2018; Uniform Plumbing Code, 2018; and 29 CFR Part 1926 (allowed in center)
  • Time limit: 2 hours
  • Exam / certification fees: USD 95 Official sources

Using Our Practice Resources

  • Work through all 100 available questions
  • Review every answer and explanation
  • Track weak areas and revisit them
  • Use our AI tutor for tough concepts

NV C-21F Chilled and Hot Water Systems: Suggested Study Strategy

1Distribute study time to the official bulletin 270 content outline (updated 3/25/2026)
2Use only the PSI-listed references; temporary tabs such as Post-it notes are prohibited
3Confirm NSCB experience documentation before scheduling with PSI
4This bank is an English-language MCQ study aid, not an official PSI form

Frequently Asked Questions

How many questions are on the Nevada C-21F Chilled and Hot Water Systems Contractor Examination?

The official PSI examination has 50 scored questions. Passing is 70% (35 of 50 points) within 2 hours (Candidate Information Bulletin 270, updated 3/25/2026).

How much does the NV C-21F exam cost?

PSI lists USD 95 for one examination portion. Two portions cost USD 140 only if the second portion is CMS. NSCB charges a separate USD 300 application fee and USD 600 biennial license fee.

Is the NV C-21F exam open book?

Yes. PSI lists this examination as open book. Uniform Mechanical Code, 2018; Uniform Plumbing Code, 2018; and 29 CFR Part 1926 (allowed in center)

Do I still need the CMS examination?

CMS is the required Nevada business-and-law examination. Most new applicants must pass CMS and a trade examination for the requested classification. In most cases you will not retake an exam if you have actively served as a qualified employee in the same classification within the last four years.