Industrial Build Quality: Constructed with high-grade traces and components to resist vibration and thermal stress common in HVAC cabinets

the 4520-0011-000 is normally closed and should only open when reaching the 300°F set point

When executing a thermostat replacement

If the return water temperature fails to reach the specified setpoint or the boiler stays in bypass mode too long

Fenwal 12-E27121-000-03 Sensor Els PW 17895 Industrial Build Quality: Constructed withThe Fenwal 12 E27121 000 03 is a precision engineered Detect A Fire vertical mount thermal sensor designed for rapid response in critical fire suppression and overheat signaling applications. This rate compensated fire detector utilizes a 300 stainless steel shell and a hex brass mounting head to ensure hermetically sealed reliability in harsh environments. Configured as a close on rise thermal switch, it features a factory set activation point of