To provide a riser with automatic hot water escape system which can automatically drain both water and hot water by operating only a water drain tap.

This invention provides a riser with an automatic hot water escape system (10), which is provided with a hot water escape valve housing (12) having a large diameter hole, a middle diameter hole, a penetrating passage and a small diameter hole therein. The small diameter hole is connected with a pipe (22) branching from a hot water supply piping. An external pipe (24) is arranged to cover a secondary cold water piping. A middle diameter hole is communicating with underground through a clearance (26) between the external pipe and the outer surface of the secondary cold water piping. The hot water escape valve housing is further provided with a hot water escape valve (30) in the large diameter hole and a hot water side pressure resistant valve (32) in the small diameter hole. A spring (34) is arranged between the leading end of hot water escape valve and the leading end of the hot water side pressure resistance valve.