This is a stem-mount gauge with a center back connection

Ensure the transformer has sufficient VA capacity to handle the solenoid coil draw during the heating cycle

this is a pilot-operated valve

With a high-visibility 2 1/2-inch dial and a standard 1/4" NPT male inlet

Always verify the output voltage at the plug with a meter before installing to prevent "over-volting" the element

Weil McLain 635-100-022 Valve R-410A This is a stem-mount gaugeThe Weil McLain 635 100 022 3 way valve body is a professional grade replacement engineered specifically for the Weil McLain CGt Series 1 and 2 residential gas boilers. Designed to replace the VCZMS6100 U, this brass 3 port valve body is critical for maintaining precise boiler water flow control and ensuring thermal balance within hydronic heating systems. As a direct fit HVAC replacement part, it integrates seamlessly with your existing Weil McLain