As stated in the TS-7363 specification, these are systems in which the accelerator parts of more than one device are connected to a common smoke channel with a horizontal collector and the flue gases are discharged to the atmosphere through a common chimney. Cascade systems that can be manufactured as MATSINGLE AND MATDOUBLE, maximum 9 condensing boilers for Wall Mounted Boilers and the maximum number of devices that can be used for Floor Mounted Boilers should be determined according to the reports given by accredited organizations or according to the flue fluid dynamics calculation results according to TS EN 13384-2. should be selected. For the discharge of condensate formed in the flue gas line; Connections of smoke ducts and chimneys should be made with a minimum slope of 3° from the horizontal.