- The CAZ exam has 50 knowledge-based questions and requires 70% to pass, with no prerequisites.
- Five published topics: building pressure fundamentals, pressure measurements, static pressure, pressure imbalances, and CAZ testing.
- The direct remote route advertises $50 USD for one proctored attempt through ProctorU.
- This is an ESCO Group knowledge credential, not a BPI or RESNET field-assessment credential.
The CAZ Exam at a Glance
This page condenses the verified facts about Combustion Appliance Zone Certification (CAZ) into one review sheet. Skim it the night before you sit the exam, or use it as a checklist while you work through the longer CAZ Study Guide.
| Item | What the Published Sources Say |
|---|---|
| Credential | Employment Ready Combustion Appliance Zone examination |
| Governing body | ESCO Group, administered through HVAC Excellence |
| Questions | 50 knowledge-based, multiple-choice |
| Passing score | 70% |
| Prerequisites | None; prior HVAC field experience not mandatory |
| Award | Certificate of Achievement |
| Intended audience | Students and entry-level technicians, commonly at the end of a training module or course |
| Delivery | Proctored online and paper options described in the catalog |
| Direct remote price | $50 USD per exam, one attempt, proctored through ProctorU |
| Renewal rule | No issuer-published renewal rule was verified |
Seventy percent of 50 questions means you need 35 correct answers. The score math is covered in more depth in CAZ Passing Score 2026, but the working number to remember is simple: you can miss 15 and still pass.
Which CAZ This Is (and Isn't)
The acronym is shared by several unrelated credentials, so confirm you are studying the right one. The CAZ on this site is the ESCO Group Employment Ready examination on combustion appliance zones, the building-science and HVAC topic. It is linked to ESCO's Employment Ready program through the O*NET certification listing.
It is a knowledge credential. It is not a BPI or RESNET credential, and it does not include a practical field assessment. Eligibility rules, exam weights, and hands-on requirements from those other programs do not apply here. If you are still sorting out the terminology, What Is CAZ Certification? and What Does CAZ Stand For? cover the basics.
The Five Topic Areas, Condensed
The five topics below come from the exam description in the ESCO Institute HVAC Excellence catalog. They are unweighted summary topics, not an official percentage blueprint, and the issuer's public materials do not publish detailed objectives beyond these phrases. Treat each as equally likely to appear and study them as a connected chain: pressure concepts feed measurement, measurement feeds duct and system diagnosis, diagnosis explains imbalances, and imbalances explain why CAZ testing exists. For a fuller walk-through, see CAZ Exam Domains 2026: Complete Guide to All 5 Content Areas.
Domain 1: Building Pressure Fundamentals
The conceptual base. Know why air moves and what a building's pressure state means for combustion appliances.
- Pressure is a difference between two points, and air moves from higher to lower pressure.
- Positive versus negative pressure relative to outdoors.
- How stack effect, wind, exhaust fans, and duct leakage push a house away from neutral.
- Why a house that is depressurized can pull combustion gases back into living space.
Domain 2: Pressure Measurements
The practical skill of reading and reporting pressure correctly.
- Manometer use and what a reading relative to a reference point actually represents.
- Units of pressure commonly used in building diagnostics, including pascals and inches of water column.
- Why the reference location (outdoors, another zone) must be stated with every reading.
- Sign conventions: a negative reading means lower pressure than the reference.
Domain 3: Static Pressure in HVAC Systems
Pressure inside the air distribution system, which links the HVAC equipment to house-wide pressure behavior.
- Static pressure as the resistance the blower works against.
- Supply side versus return side readings and what high or low values suggest.
- How restrictions such as dirty filters, undersized ducts, or closed registers raise static pressure.
- How duct leakage can create pressure differences between rooms and zones.
Domain 4: Pressure Imbalances
What happens when pressure differences develop between spaces, and why that matters for safety.
- Room-to-room imbalances created by closed interior doors with supply registers but no return path.
- Zone-to-outdoors imbalances driven by exhaust appliances and leaky return ducts.
- How imbalances change appliance draft and can contribute to backdrafting or spillage.
- Corrective concepts such as return pathways and sealing leakage.
Domain 5: Combustion Appliance Zone (CAZ) Testing
The application layer: evaluating the zone around combustion appliances under controlled conditions.
- What a combustion appliance zone is: the space containing or serving combustion appliances.
- Why testing is done under worst-case depressurization conditions.
- The role of draft and spillage evaluation in judging whether an appliance vents safely.
- That action levels and limits come from the applicable procedure, not one assumed universal value.
Key Takeaway
The issuer's website groups building pressure knowledge and measurements together and lists static pressure, pressure imbalances, and CAZ testing alongside them. The catalog splits fundamentals and measurements into separate headings. Either way, you are studying the same five subjects.
Field Vocabulary You Should Be Able to Define
With 50 knowledge-based questions, many items test whether you can recognize the correct term in a plain-language scenario. Make sure you can explain each of these in a sentence:
- Combustion appliance zone: the room or space where combustion appliances sit and draw air, plus the connected air pathways relevant to testing.
- Backdrafting: flow of combustion gases back into the building through a vent or chimney rather than up and out.
- Spillage: combustion products escaping into the living space at the draft hood or appliance vent opening.
- Depressurization: the building or zone sitting at lower pressure than outdoors, often caused by exhaust fans, dryers, or duct leakage.
- Stack effect: pressure differences driven by temperature differences between indoor and outdoor air, strongest in cold weather.
- Static pressure: pressure exerted within a duct system, used to judge airflow resistance.
- Pressure imbalance: a measurable pressure difference between two spaces or between a space and outdoors.
- Worst-case conditions: a test configuration that deliberately maximizes depressurization to see whether appliances still vent safely.
Registration and Fee Mechanics
Two price pictures appear in the published material, and they should not be blended. Our CAZ Certification Cost 2026 breakdown goes deeper, but here is the verified summary.
| Source | What It Lists | How to Use It |
|---|---|---|
| ESCO direct remote exam page | $50 USD per examination, one attempt, ProctorU proctoring | The explicitly advertised price for the direct remote route |
| September 2026 catalog, page 10 | Suggested Retail $130 USD, Exam Online $16 USD, Exam Paper $22 USD | Catalog pricing labels for Employment Ready; not member/nonmember fees and not a substitute for the $50 direct figure |
| Virginia CTE Resource Center | $15 online, $20 paper | Older figures; do not use in place of current issuer pricing |
In practice, the price you pay can depend on whether you test through a school, training provider, or the direct remote route, and on whether the provider adds charges. If you are enrolled in a course, ask your instructor how the exam is being administered before paying anything separately. Because the direct route allows one attempt per purchase, treat your first sitting as the one that counts.
Remote Exam Day Checklist
The proctored online option has concrete technical requirements. Run through this list at least a few days before your session:
- Computer: a compatible laptop or desktop with a working webcam and microphone. Tablets, iPads, and Chromebooks are unsupported.
- Connection: reliable internet for the full session.
- Identification: a government-issued photo ID ready to show the proctor.
- Room: a private testing room where you will not be interrupted.
- Software: Guardian Browser or the ProctorU Chrome extension, installed and tested in advance.
- Scheduling: proctors are available around the clock, and booking at least 72 hours ahead avoids rush fees.
For scheduling windows and deadlines, see CAZ Exam Dates 2026. For eligibility questions, CAZ Requirements 2026 confirms there are no prerequisites to meet before you register.
What Is Not Published
A good cheat sheet is honest about its gaps. Here is what you will not find in the verified sources, and what that means for your preparation:
- Domain weights: no official percentage allocation across the five topics exists in the public material. Do not trust any site that claims to know the exact split.
- Detailed objectives: the HVAC Excellence Competency and Task List workbook was not retrievable, so no unseen objectives are claimed here.
- Pass rate: no issuer-published pass rate was verified. Our CAZ Pass Rate 2026 article explains what can and cannot be said.
- Renewal: no issuer-published renewal rule was verified, so confirm directly with ESCO or HVAC Excellence if it matters for your employer.
- Timed limit: only a secondary-source report exists, as noted above.
Because the blueprint is thin, the most reliable strategy is breadth: understand all five topics well enough to reason through a scenario, rather than betting on one area. If you are weighing effort against outcome, How Hard Is the CAZ Exam? frames the difficulty for an entry-level, knowledge-based test.
Sequencing Your Review Around the Five Domains
Because the domains build on one another, order matters more than total hours. This is the one place for a schedule, and it is tied to the CAZ content chain rather than generic habits.
Pressure Concepts and Measurement
- Cover Domains 1 and 2 together: pressure as a difference, reference points, units, sign conventions.
- Practice reading scenarios and stating the reference point out loud.
Static Pressure and Imbalances
- Cover Domains 3 and 4: what restrictions and leaks do to duct and room pressures.
- Trace cause to effect: closed door, no return path, resulting room pressure.
CAZ Testing and Full Review
- Cover Domain 5, then revisit earlier domains in light of why worst-case testing matters.
- Finish with timed practice questions on the main practice test site.
Domain 5 comes last because it only makes sense once you can explain how pressure behaves and how it is measured. For a more detailed approach, the CAZ Training overview and the full study guide expand on each stage.
Where the Credential Fits Professionally
The exam is aimed at students and entry-level technicians, so it works best as a first credential that documents baseline knowledge of combustion safety and building pressure. The Certificate of Achievement signals to an employer that you have studied the subject and passed a standardized exam, even if you have limited field time. It does not replace practical assessment credentials from other bodies, and it should not be presented as one. Relevant work settings include HVAC service, weatherization and energy-efficiency programs, and building-performance contracting, where combustion safety testing is part of the job. Browse CAZ Jobs for the roles where this knowledge shows up, CAZ Salary Guide 2026 for earnings context, and Is the CAZ Certification Worth It? for a return-on-investment view. None of those articles' figures are repeated here, so check them directly for current analysis.
Key Takeaway
If you are in a training program, the most efficient path is to take the exam soon after finishing the relevant module, while pressure concepts and testing steps are fresh. Then confirm with your instructor or employer how the credential is recognized.
FAQ
The exam contains 50 knowledge-based questions, and you need 70% to pass. That works out to 35 correct answers. Successful candidates receive a Certificate of Achievement.
No. There are no prerequisites, and prior HVAC field experience is not mandatory. The exam is intended for students and entry-level technicians, commonly at the end of a training module or course.
The direct remote route advertises $50 USD per examination with one attempt, proctored through ProctorU. The catalog separately lists Employment Ready pricing labels of $130 suggested retail, $16 online, and $22 paper, which are not the same as the $50 direct fee. Costs through a school or provider may differ.
Both proctored online and paper options are described in the catalog. The remote route requires a compatible computer with webcam and microphone, government-issued photo ID, a private room, and Guardian Browser or the ProctorU Chrome extension.
No issuer-published renewal rule was verified, so confirm directly with ESCO or HVAC Excellence. It is also not a BPI or RESNET credential; it is an ESCO knowledge certification, and those programs' eligibility rules and practical assessments do not apply to it. For more background, see CAZ Certification.