The Fenwal 12-E27120-000-05 Detect-A-Fire 225°F Open Rise device is a reliable temperature-sensitive control used in HVAC and industrial heating equipment. It operates by detecting abnormal temperature rise and activating safety mechanisms to prevent overheating or potential system damage. https://www.partshnc.com/12-e27120-000-05-fenwal-detect-a-fire-225f-open-rise