Vaillant 178973 Compatible Heat Exchanger – Dhw 20 Plates – Ecotec Plus R1 Ecotec Vuw R1
There are two types of heat exchanger that can be present, they are the primary heat exchanger and the secondary heat exchanger. The primary is present in almost all boilers and uses heat from the burner to raise the temperature of water within the system. The secondary heat exchanger only appears on combination boilers and allows the heat to be transferred between one closed system and another.
We recommend that all parts are fitted by a fully qualified gas safe certified engineer.











