This is a critical safety feature often required by code to provide a redundant seal or Proof of Closure (POC) verification

ensuring the thermocouple/thermopile generates the necessary voltage for valve operation

or hot gas service

it features a durable sleeve bearing system and supports both band and thru-bolt mounting configurations for flexible installation

Resideo AM101-US-1LF Valve 323055-751 This is a critical safetyThe Resideo AM101 US 1LF is a professional grade thermostatic mixing valve designed for precision temperature control in potable water systems and hydronic heating applications. Featuring a 3 4 inch union sweat connection, this lead free brass valve maintains stable output temperatures between 70F and 145F, even under fluctuating inlet pressures. Built with a Teflon coated spool and body, it resists mineral scale buildup, ensuring long term