HVAC Procedure and Performance Guide

Attempt to start stuck hermetic (single-phase) compressor

Training for this procedure can be found in these courses:

                         131 – Oil Heat l  and  161 – Boilers l


Condition of stuck hermetic compressor must be determined to see if it can be freed and if it can be made useable.  The condition of the refrigeration system must be determined and all findings documented.  Applicable safety procedures must be followed.


  1. Review job order and manufacturer’s specifications.
  2. Collect tools, equipment and materials.
  3. Put on safety and protective equipment and apparel.
  4. Disconnect electrical power to equipment.
  5. Remove access cover(s).
  6. Set up and connect analyzer according to manufacturer’s instructions.
  7. Test capacitors and motor windings.
  8. Reconnect power to system, and using compressor analyzer, attempt to rock compressor free.
  9. If compressor starts, check for high motor current.
  10. If motor current is in acceptable range, continue to operate system and check motor current until satisfactory operation is ensured.
  11. Obtain and test oil sample for acid.
  12. Review test results and determine if replacement and/or system clean-out are required.
  13. Record findings and conclusions.
  14. Replace access cover(s).
  15. Leave system in required operating status as indicated by conclusions in Step 13.
  16. Remove safety and protective equipment and apparel.
  17. Gather tools, equipment and leftover materials, and leave work site clean.