High efficiency twin head light commercial circulator pump with 8m max head, 220 mm port-to-port length and DN40 flanged connections The Wilo Yonos MAXO range are high efficiency glandless light commercial circulator pumps designed to enable quick and simple installation. They can be used in many types of closed circuits including central heating, air conditioning and industrial applications. The Yonos MAXO-D pumps are twin head units.