Depending on the configuration of your home, if the suction cup is not suitable, the evacuation of the combustion gases will be via a flexible tube 80 mm in diameter introduced into the chimney of the building (diagram attached).
Price of the tubing: 8 (eight) meters of PP tubing, including accessories, in addition 800 € VAT 6% included (for Junkers Top 42
boilers)
Important to know: If you replace an old atmospheric boiler connected to a chimney, by a condensing boiler, it is surely necessary to pipe the chimney.