I’m new to Germany and I’m not familiar with the drainage system. My kitchen has a side room where I’ve installed a washing machine. The opening for the waste water drainage is 5 cm diameter (first picture, circled – kept plugged to block sewer gas). The main room has two large openings, 10 cm diameter, that are blocked by some metal fittings that I don’t know how to remove (second picture).
I want to check the drainage house of the washing machine to the 5 cm opening. I also want to connect the drainage hose off my sink to one of the 10 cm openings. I assume that I need a fitting, but I don’t know exactly what I need. Can anyone help me out? Danke schön!