HVAC Procedure and Performance Guide

Replace solenoid coil

Training for this procedure can be found in these courses:

                         131 – Oil Heat l  and  161 – Boilers l


Solenoid coil must be replaced according to manufacturer’s specifications. Coil must be correct type, voltage, wattage and service rating for application.  Coil must be correctly installed in housing or on plunger.  Connections must be mechanically secure and electrical continuity must be established.  Connections must be contained within solenoid wiring box.  Applicable safety procedures must be followed.


    1. Review job order and manufacturer’s specifications.
    2. Collect tools, equipment and materials.
    3. Locate solenoid with coil to be replaced and review nameplate data.
    4. Determine coil type, voltage, wattage and any special service requirements.
    5. Put on safety and protective equipment and apparel.
    6. Disconnect electrical power to equipment.
    7. Remove access cover(s).
    8. Remove old coil.
    9. Verify that new coil is suitable replacement.
    10. Install new coil in housing or on plunger.
    11. Make electrical connections and install wiring-box cover.
    12. Ensure that nameplate is securely installed and visible.
    13. Start equipment and check operation of solenoid.
    14. If equipment does not operate to specifications, troubleshoot and make required adjustments and repairs.
    15. Replace access cover(s).
    16. Leave equipment in required operating status.
    17. Remove safety and protective equipment and apparel.