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United States · Certification test

EPA Type 3 certification for low-pressure appliances

Type III is the Section 608 certification for low-pressure appliances, which use a refrigerant with a saturation pressure below 45 pounds per square inch absolute (psia) at 104°F. The Environmental Protection Agency’s (EPA’s) examples are systems running R-11, R-123, R-113 or R-245fa, and its Type 3 test topics are built around chillers. EPA Type 3 certification takes Core plus the 25-question Type III section, closed-book and proctored.

  • 130°FOil temperature before you remove it
  • Vapor firstWhen recharging, before liquid
  • 25 millimeters of mercuryAbsolute pressure to reach before opening
Where to study

Updated October 2026 · Written from official sources, listed at the bottom of this page

Who needs EPA Type 3 certification?

Anyone who maintains, services, repairs or disposes of low-pressure appliances. These systems work below atmospheric pressure, so EPA’s topics look at leaks into the system rather than out of it, such as a purge unit running more than it should, and at the job the purge unit does.

Type III on its own doesn’t cover high-pressure equipment or small appliances. Add Type I and Type II to it and you have Universal.

EPA universal certification →

Recovery and evacuation rules for Type III

  • Evacuate a low-pressure appliance to 25 millimeters of mercury absolute before opening it, whatever the age of your recovery equipment.
  • For a repair that isn’t major and isn’t followed by evacuation to the environment, pressurize the system to 0 pounds per square inch gauge (psig) before opening it. Methods that need purging afterwards, such as nitrogen, are only allowed on R-113 systems.
  • Change oil only after taking the system, or the receiver you drain the oil into, to 5 psig or less.
  • Heat the oil to 130°F before removing it, so less refrigerant comes out with it.
  • Circulate or drain the water in the chiller while you evacuate, so the tubes don’t freeze.

What’s on the Type III section

EPA’s other test topics for Type III:

  • Leak testing methods in order of preference: controlled hot water or a built-in heating or pressurization device such as Prevac, then nitrogen
  • The maximum leak test pressure for low-pressure centrifugal chillers
  • Leak inspection rules for appliances over the leak rate, and reporting chronically leaking appliances
  • Allowable annual leak rates for commercial and industrial process refrigeration and for other appliances over 50 pounds
  • Recovering vapor as well as liquid, and the high-pressure cut-out level on recovery devices used with low-pressure systems
  • Recharging: vapor before liquid so water in the tubes doesn’t freeze, through the evaporator charging valve on centrifugals
  • Evacuation levels for disposal, major and non-major repairs, leaky and non-leaky systems, and charges under or over 200 pounds
  • Pressure-temperature relationships of low-pressure refrigerants
  • Equipment room rules under ASHRAE Standard 15 (from the American Society of Heating, Refrigerating and Air-Conditioning Engineers), including a refrigerant sensor for R-123
EPA 608 study guide: Core topics →

Leak repair for chillers

EPA lists chillers among comfort cooling appliances, so the trigger leak rate is 10 percent over 12 months. Chillers with 50 pounds or more of an ozone-depleting refrigerant such as R-11 fall under Part 82. Since January 1, 2026, chillers with 15 pounds or more of a hydrofluorocarbon (HFC) refrigerant with a global warming potential above 53 fall under Part 84. The deadlines are the same and are on the Type II page.

Leak repair rules on the Type II page →
Sources: eCFR · EPA and 4 more. Checked October 2026.

Rules and fees can change, so check the official site before your test.

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