I am new here in the forum and would like to welcome everyone. I have been driving a Phaeton for about 3 months, built in 2003. This one has a problem with the heating from the beginning. And this describes itself as follows. In the stand the ventilation gets nice warm. The temperature of the cooling water is constant to 90 degrees. As soon as I start at the cold temperatures, the ventilation becomes colder and colder to completely cold. However, the engine temperature remains at 90 degrees. In the workshop the water pump and the thermostat have already been changed. However, without success. In the fault memory there are two entries available. Once the storage valve and the air valve. However, according to the workshop, this error has nothing to do with this problem. Furthermore, the stationary heating runs without problems, hoses become warm, but it only arrives cold air inside. If that helps further. I hope I have not forgotten anything and you can help me further. Thanks already in advance.