HVAC Procedure and Performance Guide

TASK: Replace electronic expansion valve

Training for this procedure can be found in these courses:

                         131 – Oil Heat l  and  161 – Boilers l


Electronic expansion valve must be installed according to manufacturer’s specifications and job specifications.  Valve must be specified size and capacity for application.  Valve must meter refrigerant into evaporator at specified rate and must provide desired refrigerant superheat.  Valve must not leak.  Applicable safety procedures must be followed.


        1. Review manufacturer’s specifications, job specifications and job order.
        2. Collect tools, equipment and materials.
        3. Put on safety and protective equipment and apparel.
        4. Determine type of connection and correct location for valve, thermistor well and equalizer.
        5. Verify that valve is specified size and type and has required capacity and voltage rating for application.
        6. Prepare tubing for expansion valve, install equalizer connection and install thermistor well.
        7. Connect expansion valve according to manufacturer’s specifications.  (Note:  Disassembly and reassembly may be required with soldered connection.  Do not direct heat on main body when soldering.  Use heat-trap paste if additional protection is required).
        8. Install equalizer line according to manufacturer’s specifications.
        9. Install and connect thermistor according to manufacturer’s specifications.
        10. Connect electrical power supply.
        11. Test valve connections for leaks.
        12. Remake connections if the valve leaks.
        13. Place system in operation.
        14. If equipment does not operate to specifications, troubleshoot and make required adjustments and repairs according to manufacturer’s specifications.
        15. Make final inspection of work.
        16. Leave equipment in required operating status.
        17. Remove safety and protective equipment and apparel.
        18. Gather tools, equipment and leftover materials, and leave work site clean.