Q: How to replace the pressure cycling switch in an air conditioning system?
A: To replace the HVAC Pressure Switch in an air conditioning system, it is recommended to have a professional air conditioning technician discharge the refrigerant. Once the refrigerant has been discharged, unplug the electrical connector from the pressure cycling switch and unscrew the switch, making sure to hold the fitting on the line with a wrench to prevent any damage. Before installing the new switch, lubricate the switch O-ring with clean refrigerant oil compatible with R134-a systems. Screw the new switch onto the threads and reconnect the electrical connector. Finally, it is important to have the system evacuated, charged, and leak tested by the shop that discharged it.