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Free NATE practice · Trades

NATE practice test: free Core questions and NATE’s published blueprint

The NATE Core exam is 50 closed-book questions in 90 minutes, and you need 70 percent, or 35 correct, to pass. Core is required for most installation and service specialty certifications, which run 100 questions each. NATE publishes its own Core weighting, with Basic Electricity at 26 percent, and certification lasts two years.

Formally the North American Technician Excellence certification. Awarding body: North American Technician Excellence, Inc.. Neuron Trainer is an independent study app and is not affiliated with, endorsed by or sponsored by the organization that owns this exam.

Get the NATE app free Jump to the practice questions

NATE at a glance, with the source for every line

Every row below is quoted from a document published by NATE and carries the date we checked it. Where NATE publishes nothing, the row says so instead of quoting a number from somewhere else.

The Core exam
Closed book · 1.5 hour time limit · 50 questions.Source: NATE (North American Technician Excellence), Core Exam KATE, verified 7 August 2026
Core passing score
For the NATE professional level certification exams, the Core and installation/service specialty exams, a score of 70% or higher is required to pass. For the Core exam, this means you must answer 35 of the 50 questions correctly to pass.Source: NATE (North American Technician Excellence), Frequently Asked Questions, verified 7 August 2026Checked against NATE’s FAQ on 2026-08-07: the 70 percent is NATE’s own published Core standard and is unrelated to the app’s 70 percent practice threshold, which is a separate in-app readiness target.
Specialty exams
For the installation and service specialty exams, you must answer 70 of the 100 questions correctly to pass.Source: NATE (North American Technician Excellence), Frequently Asked Questions, verified 7 August 2026
Why Core comes first
This exam is designed for technicians in the HVAC/R industry. This exam is a requirement for most installation or service specialty certifications.Source: NATE (North American Technician Excellence), Core Exam KATE, verified 7 August 2026
How long it lasts
NATE certification lasts two years, except for the Ground Source Heat Pump Installer Certification which lasts three years.Source: NATE (North American Technician Excellence), Frequently Asked Questions, verified 7 August 2026
Recertifying
Every NATE certified technician has an account they can log into. Your account keeps track of CEHs accrued for each of your specialties so you are aware of your progress towards recertification every two years.Source: NATE (North American Technician Excellence), Frequently Asked Questions, verified 7 August 2026
Experience
Any technician working in the HVAC industry is welcomed to take our certification exams. We recommend candidates have the following work experience as well as some experience with equipment in their specialty: One year of experience for installation technician tests · Two years of experience for service technician tests · Five years of experience for senior level technician.Source: NATE (North American Technician Excellence), Frequently Asked Questions, verified 7 August 2026
If you fail
If you fail an exam, a detailed score report will become available in your account with the percentage of correctly answered questions for each exam topic domain. Each domain does not have an equal number of questions.Source: NATE (North American Technician Excellence), Frequently Asked Questions, verified 7 August 2026
How NATE writes its questions
The NATE Technical Committee, comprised of industry experts nationwide, advises NATE on the Knowledge Areas of Technician Expertise (KATEs) and all test item development. KATEs are statistically proven job task analysis from which all questions are developed.Source: NATE (North American Technician Excellence), Frequently Asked Questions, verified 7 August 2026
Senior level
The Senior Level Efficiency Analyst exam has a passing score of 75%.Source: NATE (North American Technician Excellence), Frequently Asked Questions, verified 7 August 2026
How many questions
50 questions on the Core exam. The installation and service specialty exams are 100 questions each.Source: NATE (North American Technician Excellence), Core Exam KATE, verified 7 August 2026
Pass rate
Not published by NATE. NATE does not publish a pass rate for the Core or specialty exams on its public pages.Checked against: NATE, Frequently Asked Questions, verified 7 August 2026
Specialty exam time limits
Not published by NATE. NATE does not publish a single time limit across specialty exams. Its FAQ says exam times vary and directs candidates to the KATE document for each specific exam.Checked against: NATE, Frequently Asked Questions, verified 7 August 2026
Exam fee
Not published by NATE. NATE fees were not confirmed from natex.org during this review, so no fee is stated on this page. Check NATE's policies and fees page before you register.Checked against: NATE, Frequently Asked Questions, verified 7 August 2026

Always verify: exam lengths, fees and recertification rules come from NATE, so confirm current details at natex.org and download the KATE for your specific exam before you book.

What NATE publishes as the official NATE blueprint

These weights are NATE's, quoted from the source below. They are the only weights on this page that describe the real exam.

Published by NATE and verified on 7 August 2026.
AreaWeight NATE publishes
Basic Electricity26%
Safety18%
Achieving Desired Conditions14%
Taking Temp. and Humidity Measurements14%
Tools10%
Using Basic Science10%
Basic Construction8%

Scroll the table sideways to see every column.

Source: NATE (North American Technician Excellence), Core Exam KATE, verified 7 August 2026.

What our NATE question bank covers

What this app's question bank covers — our own category shares across 651 questions, not NATE's published blueprint.
CategoryQuestions in our bankShare of our bank
Basic electricity
Circuits, motors, capacitors, contactors, controls and the meters you diagnose them with.
568.6%
Safety
Hazardous materials regulations, personal protective practice, electrical safety, brazing and soldering, container handling and confined spaces.
10416%
Taking temperature and humidity measurements
Dry bulb, wet bulb, superheat, subcooling, psychrometrics and the instruments that read them.
16325%
Achieving desired conditions
Comfort, load, airflow, dehumidification and what happens when equipment is sized by rule of thumb.
12419%
Using basic science
Heat transfer, sensible and latent heat, pressure and temperature relationships, chemistry basics.
10315.8%
Tools
Measurement, fabrication and tubing tools, plus the gauges and instruments used in evacuation and charging.
355.4%
Basic construction
Plans and specifications, duct and piping layout, building assemblies and insulation.
6610.1%

Scroll the table sideways to see every column.

Try it

5 questions from our NATE bank

Five questions from our NATE bank, one from each of the heaviest Core sections. Full explanations on every answer. No signup, no email wall.

NATE · Free practice Every answer explained. No signup, no email wall.

  1. Question 1 of 5

    During a routine service call, a technician performs a combustion analysis on a mid-efficiency gas furnace and measures 250 ppm of carbon monoxide, air-free, in the flue gas. The manufacturer's maximum allowable air-free CO is 100 ppm. What is the MOST appropriate action?
    Answer and explanation

    Correct answer: Shut down the furnace and investigate the cause of incomplete combustion before returning it to service

    Air-free CO readings above the manufacturer's maximum, especially at more than double the threshold, indicate incomplete combustion that can result from a dirty burner, cracked heat exchanger, restricted flue, or improper air-to-fuel ratio, and represent a genuine carbon monoxide poisoning hazard; the correct response is shutting the unit down and diagnosing the root cause before restoring service, per accepted combustion safety practice. Simply documenting the reading and continuing service leaves an unsafe appliance operating. Opening a window is a temporary and unreliable dilution measure, not a corrective repair, and does not address the combustion fault. Adjusting thermostat cycling does not correct the air-to-fuel ratio or the mechanical cause of incomplete combustion producing the CO.

  2. Question 2 of 5

    A technician suspects a hermetic compressor has a grounded winding after a system tripped on overload repeatedly. Using a megohmmeter between each motor terminal and the compressor shell, the technician records a reading of 0.3 megohms. What does this reading indicate?
    Answer and explanation

    Correct answer: The winding insulation has broken down and the compressor is grounded

    Insulation resistance testing with a megohmmeter checks the integrity of the winding insulation relative to the grounded compressor shell. Industry accepted practice considers readings below 1 megohm to indicate the insulation has degraded enough that the winding is grounded or trending toward failure, and the compressor should be condemned. A healthy compressor typically reads several megohms or higher, so 0.3 megohms is far outside normal range, ruling out the idle-compressor distractor. An open winding would show as infinite resistance across terminals on an ohmmeter, a separate test from shell-to-winding insulation. A shorted capacitor is diagnosed with a capacitance meter, not a megohmmeter, so it is unrelated to this measurement.

  3. Question 3 of 5

    A technician measures return air at 75°F dry bulb and supply air at 55°F dry bulb across a cooling coil, with no measurable change in moisture content between the two readings. This temperature change represents which type of heat transfer?
    Answer and explanation

    Correct answer: Sensible heat

    Sensible heat is heat that changes a substance's temperature without changing its moisture content or physical state, and it is measured with a dry-bulb thermometer — exactly what occurs here. Latent heat is wrong because it involves a phase or moisture change (measured by wet-bulb depression), which the scenario rules out. Specific heat is a material property, not a heat transfer category. Total heat (enthalpy) combines both sensible and latent components, but only sensible change is described.

  4. Question 4 of 5

    A residential air conditioning system was sized using a rule-of-thumb estimate (500 sq ft per ton) rather than a Manual J load calculation, resulting in an oversized unit. Which comfort complaint is MOST likely to result?
    Answer and explanation

    Correct answer: Excessive indoor humidity due to short-cycling

    Oversized equipment satisfies the thermostat's sensible temperature setpoint quickly, producing short run cycles. Since moisture removal (latent capacity) requires sustained airflow across a wet coil, short cycles reduce dehumidification, raising indoor RH even though temperature feels acceptable. Reduced coil airflow is a filter or blower issue, not an oversizing symptom. Elevated static pressure results from duct design flaws. Increased subcooling is a charge-related symptom, not caused directly by capacity mismatch.

  5. Question 5 of 5

    A technician has connected a micron gauge to a system undergoing evacuation. To confirm the system is ready for refrigerant charging, the gauge should hold steady at or below which vacuum level during a decay test?
    Answer and explanation

    Correct answer: 500 microns

    A deep vacuum of 500 microns or lower, held steady during a decay test, confirms the system is dry and free of non-condensables per EPA-recommended evacuation practice. Readings of 1500 or 3000 microns still indicate residual moisture or air that can react with refrigerant oil to form acids. 29.9 inHg is a coarse compound-gauge reading barely below atmospheric pressure and lacks the resolution to detect moisture removal, reflecting confusion between inches-of-mercury and micron measurement scales.

Where NATE Core candidates actually lose points

Basic electricity is 26 percent and people study it fifth

NATE publishes the weighting and it is not subtle: electricity is more than a quarter of Core, larger than safety, and more than triple basic construction. Techs who do mostly mechanical work skim it and lose more points there than anywhere else. Megohmmeter readings, running amps against RLA, capacitors and contactor logic are the recurring shapes.

Safety is 18 percent and it is regulatory, not common sense

The KATE lists hazardous materials transport rules, MSDS documentation, confined space regulations and container handling. Knowing how to be careful is not the same as knowing what the regulation requires, and Core tests the second one.

Sensible and latent are a whole scoring category

Basic science plus temperature and humidity measurement is 24 percent between them, and most of it hinges on whether a described change moved temperature, moisture, or both. Dry bulb changes with no moisture change is sensible. If you cannot make that call instantly you will bleed points across two sections.

Oversizing questions are comfort questions, not capacity questions

An oversized system short-cycles, which kills dehumidification, so the symptom is a clammy house at the right temperature. Candidates reach for airflow or charge faults instead of the load calculation that caused it.

500 microns, not inches of mercury

A compound gauge bottoms out around 29.9 in Hg and cannot see the difference between a dry system and a wet one. Evacuation questions are testing whether you know that a micron gauge and a decay test are the only instruments that answer the question.

How long to study for NATE Core: two weeks, weighted like the exam

This plan is for Core, and it is weighted the way NATE weights the exam rather than the way the material feels. Add a dedicated block per specialty exam you intend to sit, and download that exam’s KATE first, because the weighting will be different.

Week 1, days 1–3: basic electricity

Twenty-six percent of the exam gets three days. Circuits and Ohm’s law, motor types, capacitors, contactors and relays, and the meters: ammeter, ohmmeter, megohmmeter. Run Topic Drill on the electricity category until you stop second-guessing.

Week 1, days 4–5: safety

Eighteen percent, and it is mostly regulation and documentation rather than instinct. Hazmat handling and transport, MSDS, brazing and oxy-acetylene safety, confined spaces, electrical safety and GFI requirements.

Week 2, days 1–3: measurement, science and desired conditions

Thirty-eight percent combined. Sensible versus latent, psychrometrics, superheat and subcooling, load calculation and what oversizing does to humidity. These three sections reinforce each other, so study them together rather than in isolation.

Week 2, days 4–5: tools and basic construction

Eighteen percent combined, the two most commonly skipped sections, and the cheapest points on the exam. Measurement and fabrication tools, tubing tools, duct joints, plans and specifications, insulation.

Week 2, days 6–7: full simulations

Run the Exam Simulator at Core length, 50 questions in 90 minutes, until your readiness score stops moving. NATE’s own failed-exam score report is per-domain, so train yourself to read your weak sections the same way.

Is the NATE Core exam hard?

Core is a breadth exam, and that is what makes it awkward rather than difficult. Fifty questions have to cover seven areas, so nothing goes deep, but nothing is optional either. A tech with five years on residential split systems will find the electricity, science and measurement material comfortable and then get surprised by basic construction, which is duct fabrication, plans and building assemblies and is easy to have never formally learned.

The 70 percent pass mark means 15 wrong answers is survivable, which sounds forgiving until you realize a weak section can cost you most of that budget on its own. The published weighting is the study plan: if you are short on time, hours spent on basic electricity are worth more than three times hours spent on basic construction. Our bank matches NATE’s format exactly, all 651 questions single-choice with no calculation entry, and it is filed under NATE’s own seven sections rather than an even split. Our shares are not NATE’s weights, though, and on the section that matters most they run the other way: NATE weights basic electricity at 26% while our bank puts 56 of its 651 questions there, 8.6 percent, and our largest section is taking temperature and humidity measurements at 163. Both tables are on this page. Study to NATE’s, not to ours.

NATE does not publish a pass rate, so there is no honest number to give you here.

How the NATE differs from the exams beside it

NATE tells you exactly how heavily each Core section counts, and studying to that weighting rather than to your instincts is most of the work. It is also voluntary, unlike EPA 608, so nobody is forcing you to sit it. What it buys you is the thing employers actually check. And it carries a two-year clock: pass EPA 608 once and you are done forever, pass NATE and you are back in two years earning continuing education hours. Core is also a gateway rather than a destination. Passing it does not certify you in anything on its own, it unlocks the installation and service specialty exams that do.

Questions people actually ask about the NATE

How many questions is the NATE Core exam?

50 questions, closed book, with a 1.5 hour time limit, per NATE’s published Core KATE. You need 35 of the 50 correct to pass.

What is the passing score for NATE?

70 percent for the Core and the installation and service specialty exams. That is 35 of 50 on Core and 70 of 100 on a specialty. The Senior Level Efficiency Analyst exam is the exception at 75 percent.

How long does NATE certification last?

Two years, except Ground Source Heat Pump Installer, which lasts three. You keep it current with continuing education hours tracked in your NATE account, so the two-year clock is a rhythm rather than a re-sit.

Do I need the Core exam before a specialty exam?

For most of them, yes. NATE states Core is a requirement for most installation or service specialty certifications. Core on its own does not certify you in a specialty, it opens the door to one.

Do I need experience to take a NATE exam?

No. Any technician working in the HVAC industry can sit one. NATE recommends one year of experience for installation tests, two for service tests and five for senior level, but those are recommendations rather than gates.

What happens if I fail a NATE exam?

You get a detailed score report in your account showing the percentage you answered correctly in each topic domain. That per-domain breakdown is genuinely useful, so treat a fail as a study plan rather than a verdict.

Is NATE the same as EPA 608?

No. EPA 608 is a federal requirement to handle refrigerant and never expires. NATE is a voluntary competency certification that lasts two years. Many technicians hold both, and NATE is one of the organizations that administers EPA 608 exams.

Are these real questions from the actual NATE exam?

No. NATE develops its questions from its own Knowledge Areas of Technician Expertise, and reproducing live items would violate exam security. These are original questions written to the same KATE topic areas, format and difficulty, each with a full explanation of why the right answer is right.

Practice another Trades exam

Skilled trades, HVAC & food safety. Every one of these pages is built the same way: sourced facts, an honest admission where the sponsor publishes nothing, and free practice questions.

The app

Practice the NATE in the app

The NATE app ships 651 questions, all single-choice, each with a written explanation. Its category structure follows NATE’s own seven Core sections, so Topic Drill maps one-to-one onto the areas your score report will break down if you fail. The Exam Simulator runs 50 questions in 90 minutes, matching NATE’s published Core specification exactly, though its scoring threshold is our own practice target. It includes a calculator for the measurement and load questions. NATE Test Prep 2026 went live on the App Store on 8 August 2026, free to download. It has no ratings yet, so there is no star average here. It is free to start, and Premium unlocks the full bank and unlimited AI tutor explanations; the free tier gives you three.

  • Smart Quiz — keeps returning to the categories you keep missing
  • Topic Drill — one category at a time, on its own
  • Exam Simulator — a fixed-length timed paper (50 questions in 90 minutes, as this app sets it). It does not get harder as you go; the length and the mix are fixed.
  • AI tutor — re-explains any question in plain English
  • Progress tracking, reported per category
  • On-screen calculator
  • Study reminders
  • Light and dark themes

The app calls you ready at 70% on its own simulator. That is an in-app practice target we chose, not NATE's passing standard.

Get NATE Test Prep 2026 free on the App Store

Listed on the App Store as NATE Test Prep 2026. Free to download; Premium unlocks the full bank and unlimited tutor explanations.

Walk into Core knowing where the points are.

651 questions mapped to NATE’s own seven Core sections, each with a full explanation, plus a 50-question timed simulation and an AI tutor for the electrical material that carries the most weight.

Download free on the App Store

Sources, and when we last checked them

This page was last reviewed on . The 11 facts quoted above were last checked against their sources on . Where NATE publishes nothing, the table above says so rather than guessing.

NATE is a trademark of North American Technician Excellence, Inc. Neuron Trainer is not affiliated with, endorsed by, or a recognized training provider for NATE. The name is used here only to describe the exam this app prepares you for.