by venting one port to the atmosphere

preventing terminal arcing and heat buildup

minimizing field service requirements

Proper installation ensures consistent HVAC furnace maintenance and reliable heating cycles throughout the season

Common Questions: Does this cover include a thermometer

McDonnell & Miller 157-1 Replacement Casting 30067439-890 by venting one port toThe McDonnell & Miller 157 1 Replacement Casting is a mission critical component for maintaining the structural integrity of Series 157 low water cut offs. As a heavy duty boiler water column casting, this unit serves as the primary float chamber for combination LWCO and pump controllers in high pressure steam applications. For technicians managing industrial or commercial systems, utilizing an authentic 157 1 body casting ensures precise alignment