Closed Recirculating Water Systems: What is a closed system and what problems can occur? Severn Trent Services ≻ Posts tagged "cold water system" Posted on November 7, 2023November 3, 2023 Greetings all. Last month we completed our journey through the perils of Legionella risk assessments, this month we are switching gears somewhat and shifting our focus to Closed recirculating water systems. Continue reading