Viessmann 7823858 Plate Heat Exchangerdhw - From 14.01.2005 Unitl 05.11.2008

There are two kinds of heat exchanger that can be present, the primary heat exchanger and the secondary heat exchanger. The primary is present in almost all boilers and it allows the heat to be transferred from the burner to the water within the system. The secondary heat exchanger is exclusive to combination boilers and allows the heat to be transferred between multiple closed systems. The Primary Heat exchanger is sometimes known as the heat engine or "main" heat exchanger. The secondary heat exchanger can also be known as the plate heat exchanger or the domestic hot water heat exchanger .