Grundfos UPS 25-55N (180) Hot Water Service Circulator 240V. The Grundfos UPS 25-55N (180) Hot Water Service Circulator is suitable for domestic Hot Water applications up to 110°C. The pump is of the canned rotor type, i. Pump and motor form an integral unit without shaft seal and with only two gaskets for sealing. The bearings are lubricatd by the pumped liquid. The pump is characterized by. Ceramic shaft and radial bearings. Stainless steel rotor can and bearing plate. Stainless steel pump housing. Minimal maintenance, long life. This pump has 180mm port to port dimensions and requires 1.5 inch fittings. Fittings are not supplied with the pump but are available as an optional extra.