Grundfos Pumps has introduced its Comfort Series Instant Hot Water System, a water circulation system that eliminates cold water runoff at the faucet, using a bypass valve and pump with a timer to control water flow. The Comfort Series system features a unique wet rotor design, whisper quiet operation, a built-in timer and power cord, there is no return line required, and it comes complete with pump and valve.Grundfos Pumps Corp.