OH-REF Certification

What OH-REF Certification Actually Covers

OH-REF certification refers to the Ohio Refrigeration Contractor License Exam, the trade credential administered under the Ohio Construction Industry Licensing Board (OCILB) framework. This is not an HVAC comfort-cooling license and not a general appliance repair credential. It licenses contractors who install, service, and maintain refrigeration equipment used for food and product preservation - walk-in coolers, commercial freezers, cold storage systems, and related refrigeration piping and controls found in restaurants, grocery stores, warehouses, and food processing facilities.

If you're just getting oriented, our overview of What Is OH-REF? and the plain-language breakdown at OH-REF Meaning are good starting points before you dive into exam mechanics.

Who Regulates It: OCILB and PSI

The Ohio Construction Industry Licensing Board, housed within the Ohio Department of Commerce's Division of Industrial Compliance, sets licensing rules and eligibility standards for the Ohio Refrigeration Contractor license. Actual exam delivery is outsourced to PSI, a third-party testing provider that administers the computer-based test at approved centers.

This split matters practically: OCILB handles applications, experience verification, background checks, and license issuance, while PSI handles scheduling, fees, and the testing-day experience. Understanding both sides of this process is covered in more depth in OH-REF Requirements 2026.

Exam Format and Scoring Breakdown

The trade examination totals 70 administered questions: 60 scored plus 10 unscored pretest questions that look identical to the rest but don't count toward your score. Candidates get a 3-hour time limit and must score 70% or higher to pass. Because pretest questions are indistinguishable from scored ones, treat every question on screen as if it counts.

Testing is computer-based and, notably, open-book - you're permitted to bring approved printed references rather than relying purely on memorization. This changes how you should prepare, and we unpack that strategy fully in the OH-REF Study Guide 2026.

The Five Trade Exam Domains

The 60 scored questions on the trade exam are distributed across five domains with fixed allocations. Knowing these numbers lets you prioritize study time where it actually pays off, rather than spreading effort evenly across topics that carry unequal weight.

For a deeper breakdown of what each domain actually tests and how questions are phrased, see the OH-REF Exam Domains 2026 Guide. And if you're weighing how challenging this exam is relative to other trade licensing tests, How Hard Is the OH-REF Exam? walks through the difficulty factors in detail.

The Business and Law Companion Exam

Alongside the trade exam, Ohio requires a separate Contractor's Business and Law examination. This exam has 50 scored questions plus 5 unscored pretest questions, a 2-hour time limit, and the same 70% passing requirement as the trade exam. It covers business practices, contracts, and legal obligations relevant to operating as a licensed contractor in Ohio - separate from the refrigeration-specific technical content.

Because this is billed as its own $69 PSI fee, budgeting for both exams matters. The full cost picture, including application and licensing fees, is detailed in OH-REF Certification Cost 2026.

Eligibility Requirements

Standard eligibility for the Ohio Refrigeration Contractor license requires:

• Age 18 or older
• U.S. citizenship or lawful presence status
• Five years of documented trade experience immediately preceding your application

Alternative eligibility paths exist for candidates who don't meet the standard experience track:

• An Ohio professional engineer license plus three years of trade construction-business experience
• Five years of service as an Ohio governmental trade inspector

All applicants submit documentation of their qualifying experience and must complete BCI/FBI background checks as part of the application. Full detail on documentation requirements and how OCILB verifies experience is available in OH-REF Requirements 2026.

Fees and Ongoing Costs

Budgeting for OH-REF licensure involves several separate line items rather than one flat fee:

• PSI exam fee: $69 per exam or retake (trade exam and Business and Law exam each charged separately)
• Application fee: $25
• Initial license issuance: $25
• Standard annual renewal: $60, plus 10 continuing-education hours

These add up differently depending on how many attempts you need and which renewal track you eventually qualify for. See OH-REF Certification Cost 2026: Complete Pricing Breakdown for a full line-item walkthrough.

Approved References and Open-Book Rules

Because the trade exam is open-book, what you're allowed to bring - and how you prepare it - directly affects your test-day speed. The PSI candidate bulletin (updated February 7, 2024) lists two approved references:

• The 2024 Ohio Mechanical Code
• Modern Refrigeration and Air Conditioning, 22nd edition

Advance highlighting, underlining, and tabbed indexing of these references are permitted, which means the bulk of your prep time should go toward building a fast personal index rather than memorizing text verbatim. However, handwritten notes and additional loose papers are prohibited - you cannot bring outside cheat sheets, summary pages, or annotated printouts beyond the approved texts themselves. Only PSI's onscreen calculator is allowed; personal calculators are not permitted.

For a condensed reference you can study from before test day (not to bring into the exam room), check the OH-REF Cheat Sheet 2026.

Retake Policy If You Fail

If you fail a portion of the exam, Ohio requires a 60-day waiting period before you can retest that portion. PSI allows up to five retests within a year, and each retake carries its own $69 PSI fee. Since the trade exam and Business and Law exam are scored independently, a failure on one doesn't require retesting the other - you only pay again for the portion you didn't pass.

For a precise breakdown of exactly what score you need and how the 70% threshold is calculated across scored questions, see OH-REF Passing Score 2026.

Building a Domain-Weighted Prep Plan

Given the fixed domain weights, a study schedule that treats every domain equally wastes time. A more efficient structure allocates study weeks in proportion to scored-question count, front-loading Domain 1 and Domain 4 before moving to the lighter domains.

Timed practice under the 3-hour limit matters as much as content review, since open-book lookups eat into your available time if your references aren't well organized. Our practice test platform is built around these exact domain weights so your practice sessions mirror the real distribution of questions.

License Renewal and the Compliant Contractor Program

Once licensed, standard renewal costs $60 annually and requires 10 continuing-education hours. Ohio also offers a Compliant Contractor Program for existing licensees who qualify after a compliant year of licensure. Contractors admitted to this program can choose between:

• 8 continuing-education hours for standard annual renewal, or
• 24 continuing-education hours for a $180 three-year renewal cycle

This program rewards established, compliant contractors with reduced annual paperwork by extending the renewal cycle. It's worth planning for once you're a few years into holding the license, since it changes your long-term continuing-education math.

If you're still deciding whether pursuing this license fits your career plans, Is the OH-REF Certification Worth It? weighs the licensing costs and requirements against the career outcomes. And if you want a broader library of practice questions organized by domain before scheduling with PSI, start at our OH-REF practice test homepage.

Frequently Asked Questions