HVAC Procedure and Performance Guide

Install pressure switch (high, low and oil)

Training for this procedure can be found in these courses:

                         131 – Oil Heat l  and  161 – Boilers l


Pressure switch must be installed according to manufacturer’s specifications.  Switch must control equipment operation based on pressure as specified.  Applicable safety procedures must be followed.


  1. Review job order and manufacturer’s specifications.
  2. Determine type of pressure switch to be installed.
  3. Collect tools, equipment and materials.
  4. Put on safety and protective equipment and apparel.
  5. Remove access cover(s).
  6. Connect refrigeration manifold gage set to system.
  7. Verify that new switch is suitable replacement.
  8. Disconnect electrical power to equipment.
  9. Disconnect switch pressure-sensing line from system:
  10. Isolate switch from refrigerant circuit if possible, or if not possible:
  11. Bleed or remove charge from system.
  12. Disconnect wiring and remove switch.
  13. Position switch and reconnect wiring according to manufacturer’s specifications.
  14. Connect switch pressure-sensing line.
  15. Turn on power and verify that correct voltage is available to switch.
  16. Purge or evacuate system and recharge as required.
  17. Check system for leaks.
  18. Place system in operation and adjust pressure switch according to manufacturer’s specifications.
  19. If equipment does not operate to specifications, troubleshoot and make required adjustments and repairs.
  20. Replace access cover(s).
  21. Leave equipment in required operating status.
  22. Remove safety and protective equipment and apparel.
  23. Gather tools, equipment and leftover materials, and leave work site clean.