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Chiller maintenance checklist: sources and guidance

A periodic maintenance record for one commercial or industrial chiller. The mechanical checks follow the manufacturer's instructions and your maintenance plan. The refrigerant items follow EPA's leak repair rules, which name chillers as comfort cooling appliances [7] and make the owner calculate the leak rate every time refrigerant is added to a covered appliance [24] [67].

How often: Follow the manufacturer's instructions for the chiller, or the interval set by your organization's maintenance plan. EPA's periodic leak inspections start only after a covered chiller exceeds its leak rate limit.[35][79]

Purpose

Use this chiller maintenance checklist to record a periodic service of one water-cooled or air-cooled chiller: isolation, the refrigerant circuit, compressor oil, evaporator and condenser readings, safety cutouts, and what happened to the refrigerant. Chillers differ widely by make and compressor type, so the mechanical checks point to the manufacturer's instructions rather than giving numbers. The refrigerant items follow EPA's leak repair rules for large appliances in 40 CFR 82.157 and 40 CFR 84.106, which is where the law sets duties for chiller owners.

Who should use it

Facility engineers, chief engineers and HVAC maintenance staff who look after chillers, and the service contractors they bring in. Readings and visual checks can be done by trained site staff. Anyone who could be expected to open the refrigerant circuit must pass a certification exam from an approved technician certification program [57] [56], and leak inspections after a leak rate exceedance are done by a technician holding that certification [29] [73].

How often

Use the interval in the manufacturer's instructions or your maintenance plan; many sites keep daily operating logs and a fuller service at set intervals. EPA's rules do not set a routine maintenance interval for chillers. They set leak inspection schedules only for a covered appliance that has exceeded its leak rate limit [35] [79].

How to use this checklist

  1. Fill in the chiller details. Use one record per independent refrigerant circuit, because EPA counts each independent circuit as a separate appliance [6] [58].
  2. Lock out the chiller, its starter or drive and its control power, prove them dead, and let drive capacitors discharge before opening panels.
  3. Work through the refrigerant circuit, compressor, water side and controls checks, comparing readings with the manufacturer's figures and earlier visits.
  4. Restore power and take the running readings once the chiller has settled.
  5. Complete the leak rate section only when refrigerant was recovered, added or removed, and the leak repair section only when a covered circuit is over its limit. Otherwise mark them N/A.
  6. Record the result, findings and the next visit date, and give the owner a copy.

The two isolation checks are marked critical. Before servicing equipment where unexpected start-up could cause injury, it is isolated from its energy source and rendered inoperative [2], and stored or residual energy is relieved and made safe [4]. Isolation and de-energization are verified before work starts [5].

What the rules say

  • Which chillers are covered. 40 CFR 82.157 applies to appliances with a full charge of 50 lb or more of class I or class II refrigerant [23]. Since January 1, 2026 [66], 40 CFR 84.106 covers a full charge of 15 lb or more [64] of a regulated HFC [95] or a substitute with a global warming potential above 53 [65].
  • Full charge. The owner determines the full charge of each covered appliance and records it with the method used [41] [42] [85] [86], choosing from four methods set out in the definitions [8] [61].
  • Leak rate. The owner calculates the leak rate every time refrigerant is added [24] [67], as a percentage of the full charge lost over 12 months at the current rate [15], using the same method for every covered appliance at the facility [18].
  • Limits. The limit is 10 percent for comfort cooling [27] [71] and 30 percent for industrial process refrigeration [26] [70].
  • Repair. Leaks are found and repaired within 30 days of the addition, or 120 days if an industrial process shutdown is needed [28] [72], and repairs are documented by an initial and a follow-up verification test [30] [74].
  • Records. Records under these sections are kept for at least three years [40] [84], including leak inspection records [53] [92] and verification test results [55] [94].
  • Handling. Refrigerant, including the liquid, is evacuated before an appliance is opened [22], and no one servicing an appliance may knowingly vent it [19].

What this checklist does not cover

  • Retrofit and retirement plans, repair deadline extensions, reports on chronically leaking appliances and the purged refrigerant exclusion under 40 CFR 82.157 and 84.106.
  • Automatic leak detection requirements in 40 CFR 84.108 and how to design or audit a leak detection system.
  • Evacuation levels, reclaimed refrigerant rules, refrigerant sales restrictions and disposal of a whole chiller.
  • Cooling tower maintenance and Legionella water management programs.
  • Pressure vessel, relief device and machinery room rules in the state and local codes your jurisdiction adopts.
  • Work on energized electrical equipment, arc flash precautions and electrical test procedures, which follow your electrical safety program and the manufacturer's instructions.
  • Safety precautions for flammable refrigerants and for ammonia or other chillers outside EPA's refrigerant management rules.
  • Acceptance limits for oil analysis, eddy current testing, vibration and water treatment, which come from the manufacturer and your service providers.
  • State refrigerant management programs that go beyond the federal rules.
  • Small split systems and packaged units, which the air conditioner maintenance checklist covers.

Questions

How often should a chiller be serviced?

Follow the manufacturer's instructions and your maintenance plan; the federal refrigerant rules do not set a routine service interval. What they do set is a leak inspection schedule once a covered chiller exceeds its leak rate limit [35]. For a comfort cooling chiller under 40 CFR 82.157 that means once per calendar year [37] until it has not leaked above the limit for one year [38]. Under 40 CFR 84.106 the yearly inspections run from the successful follow-up verification test [81].

Do EPA leak repair rules apply to my chiller?

It depends on the refrigerant and the full charge of each circuit. A circuit with 50 lb or more of class I or class II refrigerant falls under 40 CFR 82.157 [23]. A circuit with 15 lb or more of a regulated HFC or a substitute with a global warming potential above 53 falls under 40 CFR 84.106 [64] [65]. Each independent circuit counts as a separate appliance [6] [58].

What is the allowable leak rate for a chiller?

A chiller used for comfort cooling has a 10 percent limit [27] [71]; EPA lists chillers among comfort cooling appliances [7] [60]. A chiller that is industrial process refrigeration has a 30 percent limit [26] [70]. A chiller serving both counts as industrial process refrigeration when 50 percent or more of its operating capacity goes to the process [14].

What has to happen after a chiller leaks above the limit?

A technician holding EPA technician certification carries out a leak inspection to locate the leaks [29] [73], and the leaks are repaired within 30 days of the refrigerant addition, or 120 days if an industrial process shutdown is needed [28] [72]. An initial verification test follows the repair [31] [75], and a follow-up verification test is done within 10 days of a successful initial test [33] [77].

What records does a chiller owner keep?

The full charge and how it was determined [42] [86], a record of each service that includes the full charge and the leak rate with its method [52] [90], leak inspection records with the date, methods and leak locations [53] [54], and verification test results [55] [94]. Records are kept for at least three years [40] [84].

Do I have to lock out a chiller before maintenance?

OSHA's lockout/tagout standard covers servicing and maintenance where unexpected start-up or release of stored energy could cause injury [1]. The chiller is isolated from its energy source and rendered inoperative first [2], lockout devices are applied by authorized employees [3], and stored energy, such as the charge in drive capacitors, is relieved [4].

Sources

Each cited excerpt was found word for word in the official text on the date shown.

  1. [1]29 CFR 1910.147 The control of hazardous energy (lockout/tagout) (a)(1)(i) — eCFR (Office of the Federal Register). Retrieved September 24, 2026.
  2. [2]29 CFR 1910.147 The control of hazardous energy (lockout/tagout) (c)(1) — eCFR (Office of the Federal Register). Retrieved September 24, 2026.
  3. [3]29 CFR 1910.147 The control of hazardous energy (lockout/tagout) (d)(4)(i) — eCFR (Office of the Federal Register). Retrieved September 24, 2026.
  4. [4]29 CFR 1910.147 The control of hazardous energy (lockout/tagout) (d)(5)(i) — eCFR (Office of the Federal Register). Retrieved September 24, 2026.
  5. [5]29 CFR 1910.147 The control of hazardous energy (lockout/tagout) (d)(6) — eCFR (Office of the Federal Register). Retrieved September 24, 2026.
  6. [6]40 CFR 82.152 Definitions (refrigerant management) (Appliance) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  7. [7]40 CFR 82.152 Definitions (refrigerant management) (Comfort cooling) — eCFR (Office of the Federal Register). Retrieved September 24, 2026.
  8. [8]40 CFR 82.152 Definitions (refrigerant management) (Full charge) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  9. [9]40 CFR 82.152 Definitions (refrigerant management) (Full charge)(1) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  10. [10]40 CFR 82.152 Definitions (refrigerant management) (Full charge)(2) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  11. [11]40 CFR 82.152 Definitions (refrigerant management) (Full charge)(3) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  12. [12]40 CFR 82.152 Definitions (refrigerant management) (Full charge)(4) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  13. [13]40 CFR 82.152 Definitions (refrigerant management) (Industrial process refrigeration) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  14. [14]40 CFR 82.152 Definitions (refrigerant management) (Industrial process refrigeration) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  15. [15]40 CFR 82.152 Definitions (refrigerant management) (Leak rate) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  16. [16]40 CFR 82.152 Definitions (refrigerant management) (Leak rate)(1) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  17. [17]40 CFR 82.152 Definitions (refrigerant management) (Leak rate)(2) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  18. [18]40 CFR 82.152 Definitions (refrigerant management) (Leak rate) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  19. [19]40 CFR 82.154 Prohibitions (a)(1) — eCFR (Office of the Federal Register). Retrieved September 24, 2026.
  20. [20]40 CFR 82.154 Prohibitions (b) — eCFR (Office of the Federal Register). Retrieved September 24, 2026.
  21. [21]40 CFR 82.154 Prohibitions (b)(2) — eCFR (Office of the Federal Register). Retrieved September 24, 2026.
  22. [22]40 CFR 82.156 Proper evacuation of refrigerant from appliances (a) — eCFR (Office of the Federal Register). Retrieved September 24, 2026.
  23. [23]40 CFR 82.157 Appliance maintenance and leak repair (a) — eCFR (Office of the Federal Register). Retrieved September 24, 2026.
  24. [24]40 CFR 82.157 Appliance maintenance and leak repair (b) — eCFR (Office of the Federal Register). Retrieved September 24, 2026.
  25. [25]40 CFR 82.157 Appliance maintenance and leak repair (b) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  26. [26]40 CFR 82.157 Appliance maintenance and leak repair (c)(2)(ii) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  27. [27]40 CFR 82.157 Appliance maintenance and leak repair (c)(2)(iii) — eCFR (Office of the Federal Register). Retrieved September 24, 2026.
  28. [28]40 CFR 82.157 Appliance maintenance and leak repair (d) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  29. [29]40 CFR 82.157 Appliance maintenance and leak repair (d)(1) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  30. [30]40 CFR 82.157 Appliance maintenance and leak repair (d)(2) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  31. [31]40 CFR 82.157 Appliance maintenance and leak repair (e)(1) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  32. [32]40 CFR 82.157 Appliance maintenance and leak repair (e)(1)(ii) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  33. [33]40 CFR 82.157 Appliance maintenance and leak repair (e)(2) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  34. [34]40 CFR 82.157 Appliance maintenance and leak repair (e)(2) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  35. [35]40 CFR 82.157 Appliance maintenance and leak repair (g)(1) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  36. [36]40 CFR 82.157 Appliance maintenance and leak repair (g)(1)(i) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  37. [37]40 CFR 82.157 Appliance maintenance and leak repair (g)(1)(iii) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  38. [38]40 CFR 82.157 Appliance maintenance and leak repair (g)(1)(iii) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  39. [39]40 CFR 82.157 Appliance maintenance and leak repair (g)(4) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  40. [40]40 CFR 82.157 Appliance maintenance and leak repair (l) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  41. [41]40 CFR 82.157 Appliance maintenance and leak repair (l)(1) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  42. [42]40 CFR 82.157 Appliance maintenance and leak repair (l)(1)(iii) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  43. [43]40 CFR 82.157 Appliance maintenance and leak repair (l)(2) — eCFR (Office of the Federal Register). Retrieved September 24, 2026.
  44. [44]40 CFR 82.157 Appliance maintenance and leak repair (l)(2) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  45. [45]40 CFR 82.157 Appliance maintenance and leak repair (l)(2)(i) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  46. [46]40 CFR 82.157 Appliance maintenance and leak repair (l)(2)(ii) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  47. [47]40 CFR 82.157 Appliance maintenance and leak repair (l)(2)(iii) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  48. [48]40 CFR 82.157 Appliance maintenance and leak repair (l)(2)(iv) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  49. [49]40 CFR 82.157 Appliance maintenance and leak repair (l)(2)(v) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  50. [50]40 CFR 82.157 Appliance maintenance and leak repair (l)(2)(vi) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  51. [51]40 CFR 82.157 Appliance maintenance and leak repair (l)(2)(vii) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  52. [52]40 CFR 82.157 Appliance maintenance and leak repair (l)(2)(viii) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  53. [53]40 CFR 82.157 Appliance maintenance and leak repair (l)(3) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  54. [54]40 CFR 82.157 Appliance maintenance and leak repair (l)(3) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  55. [55]40 CFR 82.157 Appliance maintenance and leak repair (l)(5) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  56. [56]40 CFR 82.161 Technician certification (a)(1) — eCFR (Office of the Federal Register). Retrieved September 24, 2026.
  57. [57]40 CFR 82.161 Technician certification (a)(1) — eCFR (Office of the Federal Register). Retrieved September 24, 2026.
  58. [58]40 CFR 84.102 Definitions (Refrigerant-containing appliance) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  59. [59]40 CFR 84.102 Definitions (Certified technician) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  60. [60]40 CFR 84.102 Definitions (Comfort cooling) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  61. [61]40 CFR 84.102 Definitions (Full charge) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  62. [62]40 CFR 84.102 Definitions (Industrial process refrigeration) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  63. [63]40 CFR 84.102 Definitions (Leak rate) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  64. [64]40 CFR 84.106 Leak repair (a) — eCFR (Office of the Federal Register). Retrieved September 24, 2026.
  65. [65]40 CFR 84.106 Leak repair (a)(2) — eCFR (Office of the Federal Register). Retrieved September 24, 2026.
  66. [66]40 CFR 84.106 Leak repair (a)(4) — eCFR (Office of the Federal Register). Retrieved September 24, 2026.
  67. [67]40 CFR 84.106 Leak repair (b) — eCFR (Office of the Federal Register). Retrieved September 24, 2026.
  68. [68]40 CFR 84.106 Leak repair (b) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  69. [69]40 CFR 84.106 Leak repair (c)(1) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  70. [70]40 CFR 84.106 Leak repair (c)(2)(ii) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  71. [71]40 CFR 84.106 Leak repair (c)(2)(iii) — eCFR (Office of the Federal Register). Retrieved September 24, 2026.
  72. [72]40 CFR 84.106 Leak repair (d) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  73. [73]40 CFR 84.106 Leak repair (d)(1) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  74. [74]40 CFR 84.106 Leak repair (d)(2) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  75. [75]40 CFR 84.106 Leak repair (e)(1) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  76. [76]40 CFR 84.106 Leak repair (e)(1)(ii) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  77. [77]40 CFR 84.106 Leak repair (e)(2) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  78. [78]40 CFR 84.106 Leak repair (e)(2) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  79. [79]40 CFR 84.106 Leak repair (g)(1) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  80. [80]40 CFR 84.106 Leak repair (g)(1)(i) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  81. [81]40 CFR 84.106 Leak repair (g)(1)(iii) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  82. [82]40 CFR 84.106 Leak repair (g)(1)(iii) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  83. [83]40 CFR 84.106 Leak repair (g)(4) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  84. [84]40 CFR 84.106 Leak repair (l) — eCFR (Office of the Federal Register). Retrieved September 24, 2026.
  85. [85]40 CFR 84.106 Leak repair (l)(1) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  86. [86]40 CFR 84.106 Leak repair (l)(1)(iii) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  87. [87]40 CFR 84.106 Leak repair (l)(2) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  88. [88]40 CFR 84.106 Leak repair (l)(2)(vi) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  89. [89]40 CFR 84.106 Leak repair (l)(2)(vii) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  90. [90]40 CFR 84.106 Leak repair (l)(2)(viii) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  91. [91]40 CFR 84.106 Leak repair (l)(4) — eCFR (Office of the Federal Register). Retrieved September 24, 2026.
  92. [92]40 CFR 84.106 Leak repair (l)(5) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  93. [93]40 CFR 84.106 Leak repair (l)(5) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  94. [94]40 CFR 84.106 Leak repair (l)(7) — eCFR (Office of the Federal Register). Retrieved September 25, 2026.
  95. [95]40 CFR 84.3 Definitions (Regulated substance) — eCFR (Office of the Federal Register). Retrieved September 24, 2026.

Guidance, not legal advice. It does not replace the law, the manufacturer's instructions or your organization's competent people.