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Nevada C-1A Boiler Installation Contractor EXAM QUESTIONS
AND CORRECT VERIFIED SOLUTIONS LATEST UPDATE THIS
YEAR – JUST RELEASED
Nevada C-1A Boiler Installation Contractor Exam
10-Line Exam Coverage in Points Form
1. License Scope & Classification – C-1a Boilers authorizes installation of boilers and pipes
for hot water and steam, including fittings, valves, gauges, pumps, radiators, convectors,
tanks, fuel oil lines, chimneys, flues, insulation, and appurtenances
2. Exam Logistics – 50 questions, 2-hour time limit, 70% passing (32 correct), $95 exam fee
($140 for trade + Business/Law), semi-open book (2012 UMC, NFPA 31, NFPA 54, NFPA
85 permitted)
3. Licensing Requirements – 4 years journeyman/foreman experience within past 10 years,
4 reference certificates, background check, financial statements
(compiled/reviewed/audited by CPA depending on monetary limit)
4. Boiler Classifications – Low-pressure steam: ≤15 psi; High-pressure steam: >15 psi; Low-
pressure hot water: ≤160 psi; High-pressure hot water: >160 psi
5. Boiler Types – Fire-tube: combustion gases through tubes surrounded by water; Water-
tube: water through tubes heated externally; Condensing: recovers latent heat from flue
gases
6. Key Components & Controls – Safety/relief valve: releases excess pressure ; Low-water
cutoff: shuts down boiler when water too low ; Sight glass: monitors water level ;
Pressuretrol: controls steam pressure setpoint ; Aquastat: controls water temperature
7. Venting & Clearances – Category IV venting for condensing boilers (exhaust ≤30°C) ; 12
ft minimum clearance from vent termination to window openings (NFPA 54) ; 3 ft
minimum working clearance around boiler ; Vent termination to any opening: 36 in.
minimum
8. Gas Piping & Combustion – Pressure test must be held minimum 30 minutes (NFPA 54) ;
PVC prohibited for gas piping ; Black iron pipe, type K copper, CSST approved; Pressure
drop over distance is critical sizing factor
9. Inspections & Permits – State Fire Marshal conducts final inspections ; ASME Section I
governs power-generation steam boilers ; Annual inspection required for boilers over
100,000 lb/hr ; NAC 455C.300 requires C-1 license for installation work
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10. Water Treatment & Maintenance – Maintaining pH 8.5–9.5 prevents acidic corrosion ;
Blowdown removes sediment and impurities ; Low-water cutoff prevents dry firing;
Chemical treatment prevents scale and corrosion
COMPREHENSIVE PRACTICE QUESTIONS
Section 1: License Scope & Classification
1. Under NAC 624.190, what work is authorized for a C-1a Boiler Installation Contractor?
A) Residential plumbing and fixtures only
B) Installation of boilers and pipes for hot water and steam, including fittings, valves, gauges,
pumps, radiators, tanks, fuel oil lines, chimneys, flues, and insulation
C) Installation of solar heating systems only
D) Refrigeration and air conditioning systems
Answer: B
Rationale: NAC 624.190(2)(a) defines subclassification C-1a as: "The installation of boilers and
pipes for hot water and steam, including all related fittings, valves, gauges, pumps, radiators,
convectors, tanks and lines for fuel oil, chimneys, flues, insulation and other appurtenances."
2. A contractor holding a C-1a Boiler license may perform which of the following activities
without an additional classification?
A) Install a commercial kitchen exhaust hood
B) Install a complete hydronic heating system with radiators and circulator pumps
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C) Install a fire sprinkler system
D) Install an elevator
Answer: B
Rationale: The C-1a classification specifically authorizes installation of "pumps, radiators,
convectors, tanks" as part of the boiler system . Fire sprinklers require separate licensing, and
elevators are C-7 classification . Commercial kitchen exhaust hoods are not within the boiler
scope.
3. Under NRS 624, which activity is expressly prohibited for a C-1a boiler license holder?
A) Installing low-pressure residential boilers
B) Performing welding on boiler pressure vessels without a welding permit
C) Installing fuel oil lines
D) Installing chimney flues
Answer: B
Rationale: NRS 624 prohibits unpermitted welding on pressure vessels because it affects the
integrity of the boiler and requires a separate welding permit . Welding on pressure vessels
must comply with ASME code requirements and requires proper certification.
4. The Nevada State Contractors Board (NSCB) may discipline a C-1a licensee for:
A) Employing non-union workers
B) Using metric measurements
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C) Abandonment of a project without legal excuse
D) Failing to pay unemployment insurance
Answer: C
Rationale: Abandonment is a statutory violation under NRS 624.301 . Employing non-union
workers is legal, unemployment insurance is handled by another agency, and using metric
measurements is not prohibited.
5. Which Nevada Administrative Code section requires a contractor's license for boiler
installation?
A) NAC 455C.300
B) NAC 624.190
C) NAC 617.210
D) NAC 624.500
Answer: A
Rationale: NAC 455C.300 requires that "a person shall not undertake to, or offer to undertake
to, install, construct, add to, subtract from, improve or move any boiler or pressure vessel
unless the person holds a contractor's license issued pursuant to chapter 624 of NRS" .
Section 2: Exam Logistics & Licensing Requirements
6. How many questions are on the Nevada C-1a Boiler Installation Contractor exam?
Nevada C-1A Boiler Installation Contractor EXAM QUESTIONS
AND CORRECT VERIFIED SOLUTIONS LATEST UPDATE THIS
YEAR – JUST RELEASED
Nevada C-1A Boiler Installation Contractor Exam
10-Line Exam Coverage in Points Form
1. License Scope & Classification – C-1a Boilers authorizes installation of boilers and pipes
for hot water and steam, including fittings, valves, gauges, pumps, radiators, convectors,
tanks, fuel oil lines, chimneys, flues, insulation, and appurtenances
2. Exam Logistics – 50 questions, 2-hour time limit, 70% passing (32 correct), $95 exam fee
($140 for trade + Business/Law), semi-open book (2012 UMC, NFPA 31, NFPA 54, NFPA
85 permitted)
3. Licensing Requirements – 4 years journeyman/foreman experience within past 10 years,
4 reference certificates, background check, financial statements
(compiled/reviewed/audited by CPA depending on monetary limit)
4. Boiler Classifications – Low-pressure steam: ≤15 psi; High-pressure steam: >15 psi; Low-
pressure hot water: ≤160 psi; High-pressure hot water: >160 psi
5. Boiler Types – Fire-tube: combustion gases through tubes surrounded by water; Water-
tube: water through tubes heated externally; Condensing: recovers latent heat from flue
gases
6. Key Components & Controls – Safety/relief valve: releases excess pressure ; Low-water
cutoff: shuts down boiler when water too low ; Sight glass: monitors water level ;
Pressuretrol: controls steam pressure setpoint ; Aquastat: controls water temperature
7. Venting & Clearances – Category IV venting for condensing boilers (exhaust ≤30°C) ; 12
ft minimum clearance from vent termination to window openings (NFPA 54) ; 3 ft
minimum working clearance around boiler ; Vent termination to any opening: 36 in.
minimum
8. Gas Piping & Combustion – Pressure test must be held minimum 30 minutes (NFPA 54) ;
PVC prohibited for gas piping ; Black iron pipe, type K copper, CSST approved; Pressure
drop over distance is critical sizing factor
9. Inspections & Permits – State Fire Marshal conducts final inspections ; ASME Section I
governs power-generation steam boilers ; Annual inspection required for boilers over
100,000 lb/hr ; NAC 455C.300 requires C-1 license for installation work
, Page 2 of 113
10. Water Treatment & Maintenance – Maintaining pH 8.5–9.5 prevents acidic corrosion ;
Blowdown removes sediment and impurities ; Low-water cutoff prevents dry firing;
Chemical treatment prevents scale and corrosion
COMPREHENSIVE PRACTICE QUESTIONS
Section 1: License Scope & Classification
1. Under NAC 624.190, what work is authorized for a C-1a Boiler Installation Contractor?
A) Residential plumbing and fixtures only
B) Installation of boilers and pipes for hot water and steam, including fittings, valves, gauges,
pumps, radiators, tanks, fuel oil lines, chimneys, flues, and insulation
C) Installation of solar heating systems only
D) Refrigeration and air conditioning systems
Answer: B
Rationale: NAC 624.190(2)(a) defines subclassification C-1a as: "The installation of boilers and
pipes for hot water and steam, including all related fittings, valves, gauges, pumps, radiators,
convectors, tanks and lines for fuel oil, chimneys, flues, insulation and other appurtenances."
2. A contractor holding a C-1a Boiler license may perform which of the following activities
without an additional classification?
A) Install a commercial kitchen exhaust hood
B) Install a complete hydronic heating system with radiators and circulator pumps
, Page 3 of 113
C) Install a fire sprinkler system
D) Install an elevator
Answer: B
Rationale: The C-1a classification specifically authorizes installation of "pumps, radiators,
convectors, tanks" as part of the boiler system . Fire sprinklers require separate licensing, and
elevators are C-7 classification . Commercial kitchen exhaust hoods are not within the boiler
scope.
3. Under NRS 624, which activity is expressly prohibited for a C-1a boiler license holder?
A) Installing low-pressure residential boilers
B) Performing welding on boiler pressure vessels without a welding permit
C) Installing fuel oil lines
D) Installing chimney flues
Answer: B
Rationale: NRS 624 prohibits unpermitted welding on pressure vessels because it affects the
integrity of the boiler and requires a separate welding permit . Welding on pressure vessels
must comply with ASME code requirements and requires proper certification.
4. The Nevada State Contractors Board (NSCB) may discipline a C-1a licensee for:
A) Employing non-union workers
B) Using metric measurements
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C) Abandonment of a project without legal excuse
D) Failing to pay unemployment insurance
Answer: C
Rationale: Abandonment is a statutory violation under NRS 624.301 . Employing non-union
workers is legal, unemployment insurance is handled by another agency, and using metric
measurements is not prohibited.
5. Which Nevada Administrative Code section requires a contractor's license for boiler
installation?
A) NAC 455C.300
B) NAC 624.190
C) NAC 617.210
D) NAC 624.500
Answer: A
Rationale: NAC 455C.300 requires that "a person shall not undertake to, or offer to undertake
to, install, construct, add to, subtract from, improve or move any boiler or pressure vessel
unless the person holds a contractor's license issued pursuant to chapter 624 of NRS" .
Section 2: Exam Logistics & Licensing Requirements
6. How many questions are on the Nevada C-1a Boiler Installation Contractor exam?
