McDonnell & Miller 310802 Snap Switch Els PW 17895 the R400S-3/8 eliminates the need

the R400S-3/8 eliminates the need for external vent piping in most jurisdictions when used with a vent limiting device

soot buildup in the secondary heat exchanger

What is the maximum emergency exposure pressure

Can the glass be cleaned if it becomes obscured by oil or debris

and UBZ300 series models

McDonnell & Miller 310802 Snap Switch Els PW 17895 the R400S-3/8 eliminates the needOptimizing liquid flow control in hydronic and industrial systems requires reliable electrical feedback, and the McDonnell & Miller 310802 Snap Switch is the standard for maintaining seasonal uptime. Specifically engineered as the direct replacement snap switch assembly for FS250 series flow switches (Model SW FS250), this component ensures precise SPDT (Single Pole Double Throw) actuation. For contractors managing boiler flow switch maintenance, this