HVAC Procedure and Performance Guide

TASK: Connect pressure switch

Training for this procedure can be found in these courses:

                         131 – Oil Heat l  and  161 – Boilers l


Pressure switch must be connected according to manufacturer’s specifications.  Wiring must be mechanically secure and electrical continuity must be established.  Switch must perform functions in control circuit as specified by manufacturer.  Applicable safety procedures must be followed.


    1. Review manufacturer’s specifications and wiring diagrams.
    2. Determine number of circuits involved, number of normally open and normally closed contacts and contact rating required.
    3. Collect tools, equipment and materials.
    4. Put on safety and protective equipment and apparel.
    5. Check switch and verify that it contains required number of specified types of contacts and that switch rating is adequate for application.
    6. Disconnect electrical power to equipment.
    7. Connect wiring to designated contacts in switch according to specifications.
    8. Operate switch contacts manually and verify that contact operation is normal.
    9. Reconnect power and verify that voltage in circuits is correct.
    10. Verify that all connected components respond correctly to switch by operating system or by manually operating switch.
    11. Check equipment for correct component function as permitted by job progress; make final performance checks when completed system is placed in operation.
    12. Leave system in required operating status.
    13. Remove safety and protective equipment and apparel.
    14. Gather tools, equipment and leftover materials and leave work site clean.