The Unbranded Domestic Hot Water 20 Plate Heat Exchanger 178973 is a genuine unbranded alternative to the Vaillant 178973 DHW Heat Exchanger 20 Plates (Ecotec Plus 800 & VUW 2005 to 2010) and the Vaillant Domestic Hot Water Heat Exchanger 20038572 0020038572. There are two variants of heat exchanger, which are the primary heat exchanger and the secondary heat exchanger. The primary heat exchanger, installed within almost all boilers enables the heat transfer from the burner to the water within the system. The

• 20 Plate heat exchanger
• Alternative to Supplier Part Number 178973