HVAC Procedure and Performance Guide

TASK: Install relay

Training for this procedure can be found in these courses:

                         131 – Oil Heat l  and  161 – Boilers l


Relay must be installed according to manufacturer’s specifications.  Relay must be securely mounted, connections must be mechanically secure and electrical continuity must be established.  Coil must be rated for correct voltage and contacts must be rated for current to be applied.  Relay must perform specified function in electrical control system.  Applicable safety procedures must be followed.


  1. Review job order and manufacturer’s specifications.
  2. Determine relay type, coil voltage and contact rating required.
  3. Collect tools, equipment and materials.
  4. Put on safety and protective equipment and apparel.
  5. Disconnect electrical power to equipment.
  6. Remove old relay.
  7. Determine if new relay is a suitable replacement.
  8. Mount new relay and connect wiring according to specifications.
  9. Turn power on & verify that correct voltage is available to coil & contact circuit.
  10. Start equipment and check operation of relay; verify that equipment performs correctly.  (Note:  Adjust relay time delay to correct value as applicable.)
  11. If equipment does not operate to specifications, troubleshoot and make required adjustments and repairs.
  12. Leave equipment in required operating status.
  13. Remove safety & protective equipment & apparel.
  14. Gather tools, equipment and leftover materials and leave work site clean.