Xylem-McDonnell & Miller 158S Water Level & Pump Controller W/Snap Switch 2-SPDT 150 PSI 178402

The Xylem-McDonnell & Miller 158S 150 W/2 single-pole double-throw/Snap Switch 178402 is a two-speed snap switch intended for use in hydronic heating systems, specifically boilers. It has a 150-watt capacity and two operating modes that may be switched between. Both speeds may be quickly and easily switched between thanks to the snap action mechanism, and each speed can be independently controlled by two single-pole double-throw (SPDT) connections. In an emergency, you can manually override the automatic shut-off by using this switch in conjunction with a low water cut-off control. Automatic low-speed switching guards against low water damage to boilers.Depending on the requirement for heating, manual speed control enables energy usage to be changed. The switch automatically adjusts to low speed if the water level is detected when it is connected to a LWCO system.