Grundfos circulating pump 1/25 HP for solar domestic hot water heating. Stainless steel construction with cast iron volute. Includes line cord for plug in operation and new union gaskets. Special Grundfos unions required for connection to piping. Three speed operation. Maximum head 19 feet. This is the OEM replacement pump for SunEarthSolarStation Closed Loop pump station. This pump will replace the WILO Star 16-U pomp used in Caleffi and Shuco pump stations.