- The Number: 70% of a 150-Question Exam
- Scored Items vs. Pilot Items: Where the Math Gets Interesting
- What 70% Actually Demands in Practice
- Where the 150 Questions Come From
- Spending Your Points: A Domain-by-Domain Strategy
- Test-Day Mechanics That Protect Your Score
- If You Fall Short: Retest Rules and Costs
- A Study Schedule Built Around the Allocation
- Frequently Asked Questions
- The Certified Refrigeration Service Technician exam requires a 70% passing score on 150 multiple-choice questions in three hours.
- Ten of the 150 items are unscored pilots, so 140 questions actually count toward your result.
- Safety carries the most questions (24), followed by Compressors (16); together they make up over a quarter of the exam.
- RETA publishes question counts per domain, not official percentage weights, so plan from the counts.
The Number: 70% of a 150-Question Exam
The Certified Refrigeration Service Technician (CRST) credential, issued by the Refrigerating Engineers & Technicians Association (RETA), uses a straightforward passing standard: 70%. The exam is computer-based, delivered in English, and consists of 150 multiple-choice questions with a three-hour time limit. Those are the figures printed in RETA's 2026 CRST Exam Information Handbook (Revision 09, valid January 1 through December 31, 2026), and they are the only passing-score facts you need to build your plan around.
Notice what the handbook does not promise. It does not publish a published scaled-score range, a curve, or a domain-by-domain minimum. The requirement is stated as a single percentage. If you are weighing whether that bar is reasonable for your background, our guide on how hard the CRST exam is puts the difficulty in context, and the CRST pass rate analysis explains what is and is not publicly known about outcomes.
Scored Items vs. Pilot Items: Where the Math Gets Interesting
Of the 150 questions you will see, ten are unscored pilot items. That leaves 140 scored questions. Pilot items are questions RETA is trialing for future exams; they look identical to every other question, and you will not be told which ones they are.
The handbook states the 70% passing requirement alongside the 150-question format and the ten pilot items. It does not break out a separate scored-only calculation, and it does not tell candidates which ten items are unscored. For planning purposes, here is a conservative way to think about it:
| Item | Figure | Source |
|---|---|---|
| Total questions delivered | 150 | RETA 2026 handbook |
| Unscored pilot items | 10 | RETA 2026 handbook |
| Scored questions | 140 | 150 minus 10 pilots |
| Passing requirement | 70% | RETA 2026 handbook |
| Time limit | 3 hours | RETA 2026 handbook |
The practical lesson: do not try to guess which questions are pilots. Treat every item as if it counts, because you cannot identify the ten that do not. Candidates who spend time agonizing over an oddly worded question "because it might be a pilot" are wasting minutes they could use on items that matter.
What 70% Actually Demands in Practice
A 70% threshold sounds modest until you look at the exam's content. The CRST is an industrial refrigeration service and troubleshooting credential. The questions are drawn from 16 distinct content areas, ranging from lockout/tagout and ammonia safety to oil analysis, purger operation, bearing maintenance, and CO2 systems. Because the exam spans so many specialties, a candidate who is excellent at compressors but has never touched a purger or a leak-monitoring system can still struggle to reach 70%.
Think of the passing score as a breadth requirement wearing a percentage's clothing. You are not required to ace any one domain, but a weak spot in several of them adds up quickly. A field technician with years on a plant floor often discovers that the questions on Domain 3 (Oil Analysis) or Domain 15 (Ammonia Refrigeration Compliance) are phrased in regulatory or laboratory terms they have never used in daily work.
Key Takeaway
Because the passing mark is one overall percentage, you can afford to be weaker in a few small domains if you are strong in the large ones. But the smallest domains still contribute points, so avoid leaving any content area completely unstudied.
Where the 150 Questions Come From
RETA's handbook publishes question allocations for each of the 16 content areas, not percentage weights. In Domain 1 through Domain 16 order, the counts are 24, 16, 7, 11, 10, 6, 7, 7, 4, 13, 8, 7, 8, 7, 10, and 5, which totals 150. The handbook does not divide the ten pilot items among the domains, so you cannot know how many scored questions each domain contributes. Use the table below as a planning guide for where the question volume sits, and read it as a count of questions delivered rather than an official weighting.
| Domain | Content Area | Questions |
|---|---|---|
| 1 | Safety | 24 |
| 2 | Compressors | 16 |
| 3 | Oil Analysis | 7 |
| 4 | Condensers & Cooling Towers | 11 |
| 5 | Vessels, Piping, Valves & Controls | 10 |
| 6 | Insulation | 6 |
| 7 | Evaporators & Heat Exchangers | 7 |
| 8 | Pumps & Transfer Systems | 7 |
| 9 | Purges | 4 |
| 10 | Electric Service Motors, etc. | 13 |
| 11 | Controls Maintenance | 8 |
| 12 | Shaft & Bearing Maintenance | 7 |
| 13 | Leak Monitoring & Detection | 8 |
| 14 | Trouble Systems Operations | 7 |
| 15 | Ammonia Refrigeration Compliance | 10 |
| 16 | CO2 Systems | 5 |
Safety is the largest single block at 24 questions, and Compressors is next at 16. Together those two domains account for 40 of the 150 questions. For a full walk-through of what each content area covers, see the complete guide to all 16 CRST content areas.
Spending Your Points: A Domain-by-Domain Strategy
Since 70% is an aggregate target, the smartest preparation is to treat question counts as a budget. The following blocks highlight where concrete mastery pays off.
Domain 1: Safety (24 questions)
The biggest block on the exam and the one most candidates assume they already know. Questions reward precise procedural knowledge, not general caution.
- Lockout/tagout sequencing and verification before servicing equipment
- Personal protective equipment selection for ammonia exposure scenarios
- Emergency response awareness for releases and system upsets
- Safe work practices when opening or isolating refrigerant-containing equipment
Domain 2: Compressors (16 questions)
The second-largest domain, covering the machines at the heart of an industrial refrigeration plant.
- Compressor types commonly found in industrial plants and how they differ in operation
- Lubrication, capacity control, and unloading concepts
- Common operating problems and what the symptoms point to
Domain 10: Electric Service Motors, etc. (13 questions)
Often underestimated by mechanics who think of themselves as "refrigeration people." The heading is printed with its "etc." and the questions reflect that broad scope.
- Motor fundamentals relevant to refrigeration drives
- Electrical troubleshooting concepts a service technician must recognize
- How motor condition connects to shaft, bearing, and compressor behavior
Domain 4 and Domain 15 (11 and 10 questions)
Condensers & Cooling Towers and Ammonia Refrigeration Compliance sit near the middle of the pack, but they test very different skills: one is equipment performance, the other is regulatory knowledge.
- Condenser and cooling tower operation and water-side considerations
- Compliance concepts for ammonia refrigeration facilities
The five smallest domains (Domain 9 Purges at 4, Domain 16 CO2 Systems at 5, Domain 6 Insulation at 6, and the 7-question domains) are tempting to skip. Resist that urge. A handful of easy points from a tightly scoped domain like Purges is far cheaper to earn than the same number of points from a sprawling domain like Safety.
For a structured approach to turning this allocation into a calendar, the CRST study guide for first-attempt success expands on how to sequence your preparation.
Test-Day Mechanics That Protect Your Score
A passing score can be lost to logistics as easily as to knowledge gaps. These rules come straight from the 2026 handbook:
- Delivery: Testing is through the Kryterion Testing Network or RETA Network Testing Centers, with appointments arranged through RETA staff.
- Identification: Bring two forms of identification.
- Calculator: Bring a simple, nonprinting, nonprogrammable calculator with its memory cleared.
- References: RETA supplies the permitted onscreen references. Personal books, notes, and study-guide copies are not permitted.
- Navigation: You may flag questions and return to them later.
The flagging feature is your best tool for managing the three-hour limit. With 150 questions and 180 minutes, you have an average of roughly 72 seconds per question. Do not burn five minutes on a single troubleshooting scenario in Domain 14 (Trouble Systems Operations) while easier Safety questions wait. Answer what you know, flag what you do not, and use the remaining time for a second pass.
If You Fall Short: Retest Rules and Costs
Missing the 70% mark is not the end of the road. The handbook lays out a clear retest path:
| Item | Member | Nonmember |
|---|---|---|
| Initial application and exam fee (per handbook) | $770 | $1,065 |
| First discounted retest after failure within one year | $515 | $710 |
| Additional official practice attempts | $59 each (one attempt included with initial application) | |
The retest requires a new application and payment. The minimum interval before retesting is two weeks, and the retest must be completed within 90 days after approval and payment. Plan accordingly: two weeks is rarely enough time to repair a real knowledge gap, so use that window to review your weakest domains rather than simply re-reading everything.
Key Takeaway
One pricing detail remains unresolved in the sources reviewed for this article: RETA's program and application pages list the nonmember initial fee as $1,060, while the 2026 handbook prints $1,065. Confirm the amount on your invoice before paying rather than assuming either figure. For the full cost picture, see the CRST certification cost breakdown.
Application eligibility lasts one year from payment, and a 90-day extension must be requested before that eligibility period expires. If you are still determining whether you qualify to sit for the exam at all, start with the CRST requirements and eligibility guide: candidates need an active CARO or CIRO credential, or documentation of at least four years of progressively responsible refrigeration experience, plus compliance with the RETA Code of Conduct.
A Study Schedule Built Around the Allocation
If you have a limited number of weeks, sequence your preparation by question volume and by how likely a topic is to be unfamiliar. The timeline below is one reasonable way to do that; adjust it to your own plant experience.
Safety First (Domain 1)
- Work through lockout/tagout, PPE, and emergency response material
- Review ammonia safety concepts that overlap with Domain 15 compliance
Compressors and Oil (Domains 2 and 3)
- Study compressor operation and capacity control
- Pair with Oil Analysis, since lubrication condition explains many compressor problems
Heat Rejection and Plant Hardware (Domains 4, 5, 7, 8)
- Condensers, cooling towers, vessels, piping, valves, evaporators, and pumps
Electrical and Mechanical Upkeep (Domains 10, 11, 12)
- Electric service motors, controls maintenance, and shaft and bearing maintenance
Specialty Areas (Domains 6, 9, 13, 14, 15, 16)
- Insulation, Purges, Leak Monitoring & Detection, Trouble Systems Operations, Ammonia Refrigeration Compliance, and CO2 Systems
- Finish with a full timed practice attempt and review misses by domain
The logic is simple: front-load the domains that hold the most questions, then close with the small, specialized areas where a short burst of focused study can still yield reliable points. For a ready reference to cram from in the final days, the CRST cheat sheet condenses the must-know facts, and you can pressure-test your recall with the full-length practice exams.
Frequently Asked Questions
According to RETA's 2026 CRST Exam Information Handbook, you need 70% to pass. The exam has 150 multiple-choice questions, of which ten are unscored pilot items, and you have three hours to complete it.
No. Ten of the 150 items are pilots and do not count, leaving 140 scored questions. You are not told which items are pilots, so answer every question with full effort.
The handbook states a single 70% passing requirement and does not publish domain-level minimums. It also publishes question counts per domain rather than official percentage weights, so plan from those counts and do not rely on any claimed domain cutoffs.
The minimum interval is two weeks. A first discounted retest within one year costs $515 for members and $710 for nonmembers, requires a new application and payment, and must be completed within 90 days after approval and payment.
No. Personal books, notes, and study-guide copies are not permitted. RETA supplies the permitted onscreen references, and you may bring a simple nonprinting, nonprogrammable calculator with its memory cleared, along with two forms of identification.
Reaching 70% on the CRST is less about brilliance than about coverage: know the 16 content areas, respect the two big blocks of Safety and Compressors, and treat the small domains as inexpensive points. Once you pass, the credential is valid for three years, and you can explore what it means for your career in our analysis of whether the CRST is worth it.