McDonnell & Miller 310488 Switch Assembly Els PW 29614 Professionals trust this Lennox furnace

Professionals trust this Lennox furnace part for its exact fit and consistent resistance values across extreme thermal cycles

When should I choose the HH core over a standard core

System Protection: Acts as a primary refrigerant safety switch to prevent compressor overheating and liquid slugging during low-side pressure drops

This control is rated for 120/277V AC and is specifically designed for pilot duty applications (50VA)

or unexpected boiler modulation issues

McDonnell & Miller 310488 Switch Assembly Els PW 29614 Professionals trust this Lennox furnaceThe McDonnell & Miller 310488 is a field replaceable SWA 42S Snap Switch Assembly engineered specifically for Series 42S low water cut off and pump controllers. This single pole, single throw (SPST) mechanism provides precise automatic reset functionality, ensuring consistent boiler feed pump control and high limit safety across residential, commercial, and industrial steam applications. Built with a robust housing and high quality internal contacts,