The Johnson Controls WEL11A-601R Immersion Well is a durable protective housing designed for temperature sensors in hydronic HVAC systems. Installed in piping or tanks, it allows sensors to accurately measure fluid temperature without direct exposure to pressure or corrosive elements. Commonly used in boilers, chillers, and water loops, it ensures reliable thermal monitoring and system control. Its robust construction enhances sensor longevity, simplifies maintenance, and improves operational safety, making it an essential component for maintaining efficiency and consistent performance in commercial and residential HVAC applications.