The S1-025-26390-001 is usually mounted on the divider plate or the furnace firewall

The inclusion of the internal check valve facilitates bi-flow operation

this is a "TXV less flange" model

The unit is integrated into the boiler safety circuit

the GC10116 is designed to handle high-torque loads while maintaining precise alignment to prevent premature bearing failure and vibration-related system fatigue

McDonnell & Miller 94-A Pump Controller R-22 The S1-025-26390-001 is usually mountedThe McDonnell & Miller 94 A Pump Controller (Part Number 165500) is a heavy duty combination low water cut off and liquid level control engineered specifically for commercial and industrial steam boilers. Rated for a maximum pressure of 250 PSI, this float operated unit provides reliable burner protection and automatic feed pump cycling to maintain consistent water levels regardless of steaming capacity. Unlike standard models, the 94 A features 1 1