De Dietrich 300009825 échangeur de chaleur à plaques 24kW (plaques 12)

The De Dietrich 300009825 plate heat exchanger is listed as a 24 kW unit with 12 plates. The catalogue article and manufacturer codes are 336.781.002 and 300009825. Parts of this type transfer heat from the flue gases to the heating water; in combination boilers a secondary plate exchanger produces domestic hot water. Such heat exchangers are selected by model-specific dimensions and connections, the number of plates or flow ways, the material (stainless steel, copper, aluminium alloy), and the gasket type. Typical failures include scaling on the water side, soot deposits on the gas side, gasket leaks, and – in condensing appliances – corrosion where condensate collects. When replacing a plate heat exchanger, verify that the number of plates, the port spacing, and the gasket profile match the original; the unit’s capacity is tied to the plate count and the overall dimensions. The turbulators often fitted inside the flue passages are part of the heat exchanger assembly and slow the gas flow to improve heat uptake; their condition should be checked at the same time.