What Causes Water Hammer in Condensate Systems? (And How to Stop It)

Water hammer in a condensate system almost always means one thing: steam and condensate are mixing when they shouldn’t. In this installment of Weekly Boiler Tips we break down why condensate lines hammer, how flash steam is created, and the most common piping mistake that causes violent shock inside the system. If you’re troubleshooting banging pipes, shaking lines, or loud impacts in your condensate return, this explanation will save you time, repairs, and callbacks. Safety notice: Always consult experts for complex repairs. Weekly Boiler Tips are compiled by the knowledgeable and remarkably prolific content creators at WARE, a family owned, third-generation, 69-year-old commercial and industrial boiler rental and service firm based in Louisville KY. You can learn all about this and more at WARE's Boiler University.