EPA 608 Type III Practice Test
Updated October 26, 2026
Type III certifies you to service and dispose of low-pressure appliances, mainly centrifugal chillers that use refrigerants such as R-11 and R-123. Because these systems run below atmospheric pressure, they leak air in rather than refrigerant out, which changes how you find leaks, recover and charge. The Type III section has 25 multiple-choice questions, and you need Core too. Try the free questions below.
What Type III covers
- How low-pressure systems work, and why air and moisture get in.
- Purge units and the rupture disc.
- Leak testing a system that operates in a vacuum.
- Recovery, including the 25 mm Hg absolute evacuation level, and protecting the water in the tubes.
- Charging a low-pressure chiller.
Free EPA 608 Type III practice questions
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Why do low-pressure chillers usually leak air and moisture into the system rather than refrigerant out?Answer: BLow-pressure refrigerants like R-123 boil at relatively high temperatures, so much of the system runs in a vacuum. Any leak lets air and moisture in, which is why these chillers need purge units.
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What does a purge unit on a low-pressure chiller do?Answer: CThe purge unit removes air and other non-condensables that leak into the system, which would otherwise raise condenser pressure and reduce efficiency. High-efficiency purge units release very little refrigerant with the air. Frequent purge operation is a sign of a leak.
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On a low-pressure chiller, the rupture disc on the evaporator is typically rated to burst at:Answer: BThe rupture disc on a low-pressure chiller's evaporator is usually set at 15 psig to protect the system from overpressure. That's why leak-test pressure must stay below it, generally no higher than 10 psig.
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How can a technician raise the pressure in a low-pressure chiller for leak testing?Answer: DWarming the refrigerant with controlled hot water or heating blankets raises its pressure enough to leak-test, while keeping it below the rupture disc setting. Nitrogen can also be used, but pressure must stay within the limits for the system, generally no more than 10 psig.
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When recovering refrigerant from a low-pressure chiller, why should the water in the chiller tubes be circulated or drained?Answer: AAs refrigerant is removed, its pressure and boiling temperature drop, which can freeze the water in the evaporator tubes and burst them. Circulating the water, or draining it, prevents freezing damage.
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When charging a low-pressure chiller that is in a deep vacuum, what should be introduced first?Answer: BAdding liquid to a system in a deep vacuum makes it boil instantly at a very low temperature, which can freeze the water in the tubes. Charge vapor first until the saturation temperature is above freezing, then switch to liquid.
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To what level must a low-pressure appliance be evacuated before it is opened for service or disposal?Answer: CEPA's Table 1 requires low-pressure appliances to be evacuated to 25 mm Hg absolute, a deep vacuum, regardless of when the recovery equipment was made.
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Which refrigerant is typically used in low-pressure centrifugal chillers?Answer: CR-123 (an HCFC) and the older R-11 (a CFC) are low-pressure refrigerants used in centrifugal chillers. R-410A, R-22 and R-134a are high-pressure refrigerants covered by Type II.
Keep going
Pair this with the Core practice test. Pass Core, Type I, Type II and Type III for Universal certification.
Pass the EPA 608 exam on your first try
- All 168 questions across Core, Type I, Type II and Type III
- An explanation for every answer, with the rule or principle behind it
- Unlimited practice exams per section, scored like the real test (18 of 25 to pass)