Xylem-McDonnell & Miller 7-BM M/R Potentiometer Sw. #110900

The Xylem-McDonnell & Miller 7-BM M/R Potentiometer Sw. #110900 is likely a replacement part for a wide range of HVAC equipment, including boilers and furnaces. The Manual/Reset indicates that it has both automatic reset and manual control. Since the term "potentiometer" describes a variable resistor, this switch likely modifies electrical resistance to control a system component. a potentiometer and combo switch that may be found in furnaces or boilers in HVAC systems. This variable resistor most likely modifies a particular system parameter, such as water flow, air flow, or fan speed. exact control over essential system variables to ensure peak effectiveness and performance. ability to manually override for maintenance or troubleshooting.  Safety precautions include potentiometer resets to stop faults.