A Vaillant brand connection piece with clips and O-rings for the heat exchanger of eco MAX VU (condensing), eco MAX VUW (condensing), eco TEC VUW (condensing) and eco TEC VU (condensing) boilers. The heat exchanger transfers heat from a boiler's burner to water. A primary heat exchanger is found in all boilers, using heat from a burner to raise the temperature of the water in the system, while a secondary heat exchanger is present only in combis and allows the heat to be transferred between clos

Brand Name	Vaillant