Where is the heating circulating water pump of Audi a5?

Under the sump in the engine room, on the right.

The warm air water valve is the warm air switch of the automobile heater. The working principle of the automobile heater is that the radiator in the heater is connected with the circulating water of the engine through the inlet and outlet water pipes, and the water valve is a switch.

Large and small circulation of cooling water

Cooling water circulation path: The temperature controller can make cooling water have three circulation paths: small circulation, large circulation and mixed circulation.

It's in the drain of the engine room.