Why is the warm wind of Mercedes always cold?

If you are sure that the heating mode is turned on. Moreover, the engine coolant is used to dissipate the warm air, so it is possible that the warm air pipe is blocked or the scale in the warm air tank is too thick, which leads to poor heat dissipation. If an electric heater is used, the heater control module may be damaged.

I hope I can help you. If you have any questions, just ask.