PracticeVideosBlogFlashcardsEspañol
All Practice Exams

100+ Free NATE GS Installation Practice Questions

Pass your NATE Gas Heating (Air) Installation Specialty exam on the first try — instant access, no signup required.

✓ No registration✓ No credit card✓ No hidden fees✓ Start practicing immediately
100+ Questions
100% Free

Loading practice questions...

Same family resources

Explore More NATE HVAC Certifications

Continue into nearby exams from the same family. Each card keeps practice questions, study guides, flashcards, videos, and articles in one place.

NATE Air Conditioning Installation Specialty

Practice Questions

NATE Air Conditioning Service Specialty

Practice Questions

NATE Air Distribution Installation Specialty

Practice Questions

NATE Air Distribution Service Specialty

Practice Questions

NATE Air-to-Air Heat Pump Installation Specialty

Practice Questions

NATE Air-to-Air Heat Pump Service Specialty

Practice Questions
2026 Statistics

Key Facts: NATE GS Installation Exam

100

Exam Questions

NATE Gas Furnaces Installation KATE

2.5 hours

Time Limit (closed book)

NATE

70%

Passing Score (70 of 100)

NATE

40%

Installation Section Weight

NATE KATE

Core required

Prerequisite Exam

NATE

100

Free Practice Questions

OpenExamPrep

The NATE Gas Heating (Air) Installation specialty is a North American Technician Excellence certification for top-level HVAC installers of residential gas warm-air furnaces (up to 400,000 Btu/h). The closed-book exam has 100 multiple-choice questions delivered over 2.5 hours, with a 70% passing score (70 of 100), and requires passing the NATE Core exam first. The exam is weighted toward Installation (40%), with System Components (30%), Applied Knowledge such as codes and venting (20%), and Service (10%). It covers furnace siting and mounting, gas piping and sediment traps, metal and PVC/ABS venting, vent categories I-IV, condensate handling, combustion air per NFPA 54, ignition and safety controls, airflow and temperature rise, and start-up commissioning. This free prep includes 100 research-based practice questions with explanations and an AI tutor.

Sample NATE GS Installation Practice Questions

Try these sample questions to test your NATE GS Installation exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1When setting an upflow gas furnace on a combustible wood floor, what must the installer verify to comply with the appliance listing and the National Fuel Gas Code?
A.Any furnace may be set directly on wood with no special provision
B.The furnace is listed for floor mounting or a listed combustible-floor base is used
C.A 1-inch air gap is left under every furnace regardless of listing
D.Combustible-floor installation is never permitted for gas furnaces
Explanation: A furnace may be installed on a combustible floor only when it is specifically listed for that application or a listed sub-base (combustible-floor base) is used. The installation instructions and the appliance nameplate state the required clearances to combustibles, which the installer must follow.
2A horizontal furnace is being suspended in an attic. Which installation practice best ensures safe, serviceable operation?
A.Hang it from the flue pipe to save floor space
B.Provide a level, supported platform or hangers rated for the weight with required service clearance
C.Set it directly on unsupported ceiling drywall
D.Omit a service platform because attics are rarely entered
Explanation: Horizontal furnaces in attics must be supported by hangers or a platform rated for the unit weight and installed level (or pitched per instructions for condensing units) with code-required access and working space. This protects the structure and allows future service.
3Per the National Fuel Gas Code (NFPA 54), a space is considered a 'confined space' for combustion-air purposes when its volume is less than:
A.10 cubic feet per 1,000 Btu/h of appliance input
B.25 cubic feet per 1,000 Btu/h of appliance input
C.50 cubic feet per 1,000 Btu/h of appliance input
D.100 cubic feet per 1,000 Btu/h of appliance input
Explanation: NFPA 54 defines a confined space (for the standard method) as one having less than 50 cubic feet of volume per 1,000 Btu/h of the aggregate input of all appliances in the space. Below this threshold, additional combustion air must be provided.
4Using the standard two-opening 'all indoor air' method, each combustion-air opening connecting a confined furnace space to an adjacent room must have a minimum free area of:
A.1 square inch per 4,000 Btu/h
B.1 square inch per 1,000 Btu/h, not less than 100 square inches
C.1 square inch per 2,000 Btu/h
D.Half the appliance input in square inches
Explanation: For the all-indoor-air method with two openings into adjoining interior spaces, each opening must be a minimum of 1 square inch per 1,000 Btu/h of total appliance input, and not less than 100 square inches. One opening starts within 12 inches of the top and one within 12 inches of the bottom of the enclosure.
5When supplying combustion air to a confined space using two permanent openings drawn directly from outdoors through vertical ducts, each opening must have a minimum free area of:
A.1 square inch per 1,000 Btu/h
B.1 square inch per 2,000 Btu/h
C.1 square inch per 4,000 Btu/h
D.1 square inch per 3,000 Btu/h
Explanation: Under NFPA 54, when two openings communicate directly with the outdoors (vertical ducts), each opening must provide at least 1 square inch per 4,000 Btu/h of total input. Horizontal ducts use 1 in² per 2,000 Btu/h, and a single opening uses 1 in² per 3,000 Btu/h.
6A standard-efficiency gas furnace with an induced-draft blower venting into a metal B-vent at negative pressure and a flue temperature above the dew point is classified as:
A.Category I
B.Category II
C.Category III
D.Category IV
Explanation: Category I appliances vent at non-positive (negative) static pressure with flue-gas temperatures high enough to avoid condensation. Natural-draft and most 80% AFUE induced-draft furnaces using Type B vent are Category I.
7A 95% AFUE condensing furnace is vented in PVC and operates with a positive vent pressure and flue temperature below the water dew point. This appliance is:
A.Category I
B.Category II
C.Category III
D.Category IV
Explanation: Category IV appliances operate with positive vent static pressure and condensing (below dew point) flue temperatures, so they require gas-tight, corrosion-resistant venting such as PVC, CPVC, or polypropylene, with a condensate-handling provision.
8When installing a Category IV condensing furnace, why must the vent and condensate piping be sloped back toward the furnace (or to a drain) per the manufacturer's instructions?
A.To increase flue-gas velocity
B.To allow acidic condensate to drain and prevent blockage that trips the pressure switch
C.To reduce the required vent diameter
D.To eliminate the need for a condensate trap
Explanation: Condensing furnaces form acidic liquid condensate in the vent. The vent must pitch so condensate drains back to the furnace condensate trap/drain; standing water blocks the vent and trips the pressure/condensate safety switch, locking out the furnace.
9What is the primary purpose of the rollout switch (flame rollout limit) on a gas furnace?
A.To prove the inducer has started
B.To shut off the gas valve if flame escapes the burner compartment due to a blocked heat exchanger or vent
C.To modulate the gas valve for two-stage firing
D.To sense flame at the burner during ignition
Explanation: The flame rollout switch is a manual- or auto-reset high-limit that opens the gas-valve circuit if flames roll out of the burner box — typically from a blocked heat exchanger, plugged vent, or inadequate combustion air. It is a critical safety control protecting against fire and CO.
10During startup of a natural-gas furnace, the installer measures manifold gas pressure. A typical nominal manifold pressure for a natural-gas furnace is approximately:
A.0.5 inches w.c.
B.3.5 inches w.c.
C.11 inches w.c.
D.14 inches w.c.
Explanation: Most residential natural-gas furnaces are set to a nominal manifold (outlet) pressure of about 3.5 inches water column, with the exact value on the rating plate. LP/propane furnaces typically run near 10–11 inches w.c. Always set to the nameplate value with a manometer.

About the NATE GS Installation Exam

The NATE Gas Heating (Air) Installation specialty certifies an HVAC installer's knowledge of installing residential gas warm-air furnaces (up to 400,000 Btu/h heating capacity). The closed-book exam has 100 multiple-choice questions over 2.5 hours and requires 70% to pass, plus the NATE Core exam. Content emphasizes installation practices, system components and combustion, codes and venting, and basic service.

Assessment

100 closed-book multiple-choice questions over 2.5 hours, weighted Installation 40%, System Components 30%, Applied Knowledge 20%, Service 10%; 70% (70 correct) to pass. Requires the NATE Core (Installation) exam. This practice bank is 100 selected-response items.

Time Limit

2.5 hours

Passing Score

70% (70 of 100 questions)

Exam Fee

Approximately $100-$150 per specialty exam (set by authorized testing organizations) (North American Technician Excellence (NATE))

NATE GS Installation Exam Content Outline

40%

Installation

Furnace siting and mounting, gas piping and field wiring, metal and PVC/ABS venting, condensate drains, duct fabrication and installation, thermostats and accessories, and start-up/checkout

30%

System Components

Gas combustion fundamentals, furnace configurations, ignition systems, vent categories I-IV, safety controls, heat exchangers and burners, blowers, and combustion air

20%

Applied Knowledge

NFPA 54 combustion-air and venting rules, gas pipe sizing, NEC circuit requirements, IECC duct rules, load and design considerations, IAQ, and CO/safety regulations

10%

Service

Start-up repairs and basic diagnostics of electrical, fuel, venting, and condensate systems, plus low- and line-voltage troubleshooting fundamentals

How to Pass the NATE GS Installation Exam

What You Need to Know

  • Passing score: 70% (70 of 100 questions)
  • Assessment: 100 closed-book multiple-choice questions over 2.5 hours, weighted Installation 40%, System Components 30%, Applied Knowledge 20%, Service 10%; 70% (70 correct) to pass. Requires the NATE Core (Installation) exam. This practice bank is 100 selected-response items.
  • Time limit: 2.5 hours
  • Exam fee: Approximately $100-$150 per specialty exam (set by authorized testing organizations)

Keys to Passing

  • Complete 500+ practice questions
  • Score 80%+ consistently before scheduling
  • Focus on highest-weighted sections
  • Use our AI tutor for tough concepts

NATE GS Installation Study Tips from Top Performers

1Weight your study toward Installation (40%) and System Components (30%) — together they are 70% of the exam
2Memorize NFPA 54 combustion-air rules: confined space is under 50 ft3 per 1,000 Btu/h, and know the two-opening sizing for indoor (1 in2/1,000 Btu/h) versus outdoor air
3Know the four vent categories cold: Category I (negative, non-condensing, B-vent) versus Category IV (positive, condensing, PVC with condensate drain)
4Practice the airflow math: CFM = Btuh / (1.08 x temperature rise), and keep temperature rise within the nameplate range
5Understand the safe sequence of operation: inducer and pressure switch, then igniter, then gas valve, then flame proving, then blower fan-on delay
6Complete all 100 practice questions and review every miss with the AI tutor before sitting the exam

Frequently Asked Questions

How many questions are on the NATE Gas Heating Installation exam and how long is it?

The Gas Furnaces (Gas Heating Air) Installation specialty is a closed-book exam with 100 multiple-choice questions and a 2.5-hour time limit. You must answer 70 of the 100 correctly (70%) to pass.

What score do I need to pass the NATE Gas Heating Installation specialty?

You need 70%, which is 70 of the 100 questions, to pass. The exam is weighted toward Installation (40%), with System Components (30%), Applied Knowledge (20%), and Service (10%), so balanced study across all four areas is essential.

Do I need the NATE Core exam before the Gas Heating Installation specialty?

Yes. To become NATE-certified you must pass the NATE Core (Installation) exam in addition to this specialty. Many candidates have about one year of gas-furnace installation field experience.

How is the Installation specialty different from the Gas Heating Service specialty?

The Installation specialty focuses on setting and mounting furnaces, gas piping, venting, duct and condensate installation, and start-up/commissioning. The Service specialty focuses on diagnostics and troubleshooting of an installed system.

What codes and standards does the exam reference?

Reference materials include the National Fuel Gas Code (NFPA 54)/International Fuel Gas Code, the International Mechanical and Energy Conservation Codes, ACCA Manuals (J, D, S, QI), and SMACNA duct standards. Combustion-air and venting rules from NFPA 54 are heavily tested.

Is this free NATE Gas Heating Installation practice as good as paid prep?

Our 100 practice questions cover the same Installation, System Components, Applied Knowledge, and Service domains as the official NATE KATE outline, with a teaching explanation for every answer plus free daily AI tutor interactions. All content is free forever and updated for 2026.