an open circuit when cool indicates a failed component

vibration-resistant connection to the system control board

While the 3155 series typically requires a single gasket

leave the jumper intact

the internal bimetal disc has failed and the switch must be replaced

Parker 202420 Gasket Kit an open circuit when coolThe 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,