HVAC Procedure and Performance Guide

TASK: Determine problem in air-conditioning electrical system

Training for this procedure can be found in these courses:

                         131 – Oil Heat l  and  161 – Boilers l


Malfunctions in electrical system must be identified and required repairs determined. Applicable safety procedures must be followed.


  1. Review job order, manufacturer’s maintenance instructions and wiring diagrams.
  2. Discuss problem with user or owner.
  3. Collect tools, equipment and materials.
  4. Put on safety and protective equipment and apparel.
  5. Determine if power is available and adequate to system.
  6. Check circuit breakers and fuses.
  7. Determine if power is available to components.
  8. Check wiring connections.
  9. Disconnect circuit breakers or fuses.
  10. Perform continuity test on components; if test is good, turn power on and proceed.
  11. Start system and identify non-functioning components if system can be started safely.
  12. Identify defective components.
  13. Test defective components and determine if repair or replacement is required.
  14. Document tests and findings.
  15. Remove safety and protective equipment and apparel.
  16. Gather tools, equipment and leftover materials, and leave work site clean.