vibration-resistant connection to the system control board

A veteran technician will check for continuity across the terminals when the system is cool

While the 3155 series typically requires a single gasket

Smith systems

an open circuit when cool indicates a failed component

Parker 202420 Gasket Kit vibration-resistant connection to the systemThe Parker 202420 Gasket Kit is a critical OEM maintenance component designed for the Parker Flo Con A9 series of pilot operated pressure regulators. Engineered for industrial refrigeration and high demand HVAC systems, this kit provides a complete set of high grade gaskets and O rings required to reseal the valve body and maintain pilot circuit integrity. This kit is specifically compatible with the A9, A9B, A9E, A9S, and A9SE valve configurations,