Abstract: The invention relates to an adapter bit (6) for the parallelepiped liquid distributing section (2) of a liquid treatment device (1) which is provided in a corner area with a flattened section (3) on which the adapter bit (6) can be placed. The adapter bit (6) has a base (6?) with a liquid passage (7) corresponding to the liquid passage (4) of the flattened section (3), and a pipe conduit connection (10) which is configured as a universal connector. A base section (6?) of the adapter bit comprises a seat (11) for a temperature sensor (12) which sensor is embedded into the seat by means of a casting compound (13). A connecting cable (14) leading away from the base section (6?) comprises an electrical connector (15) via which the temperature sensor (12) is connected to a temperature control device.