HVAC Procedure and Performance Guide

Replace evaporator coil

Training for this procedure can be found in these courses:

                         131 – Oil Heat l  and  161 – Boilers l


Evaporator coil must be replaced according to manufacturer’s specifications.  Coil must be securely installed in housing, refrigerant and condensate lines must be connected and system must perform according to specifications.  Applicable safety procedures must be followed.  EPA regulations on discharge of refrigerants to atmosphere must be satisfied.


  1. Review job order and manufacturer’s specifications.
  2. Determine evaporator coil size, number of tubes, number of rows, fin spacing and coil configuration.
  3. Collect tools, equipment and materials.
  4. Put on safety and protective equipment and apparel.
  5. Disconnect electrical power to equipment.
  6. Remove access cover(s).
  7. Attach refrigeration manifold gage set and bleed pressure off system.  (Note:  Recover refrigerant if required by EPA regulations).
  8. Cut and remove refrigerant tubing sections at evaporator coil and disconnect condensate drain.
  9. Recover refrigerant according to EPA regulations.
  10. Remove old evaporator coil from housing.
  11. Verify that new coil is suitable replacement.
  12. Make modifications to housing if necessary.
  13. Position and secure new evaporator in housing.
  14. Replace liquid line filter-dryer.
  15. Nitrogen purge refrigerant tubing and make coil connections.  (Note:  This procedure will vary according to type of connection used).
  16. Reconnect condensate drain.
  17. Check system for leaks and make necessary repairs.
  18. Evacuate and recharge system.
  19. Place system in operation, check performance and make necessary adjustments.
  20. Replace access cover(s).
  21. Leave system in required operating status.
  22. Remove safety and protective equipment and apparel.
  23. Gather tools, equipment and leftover materials, and leave work site clean.