Hello filip! It depends as ther are different valve types used by Oventrop. The new ones are M30x1,5, not needing an adapter. Older M30x1,5 fit but are not ready for thermostats with a motor. And a third group is M30x1,0 that always needs an adapter. You may need to ask a pro (plumber) . Best regards, Volker
Feb 6, 2022