Valve arrangement, particularly for adjusting the flow of heating or cooling liquid in a motor vehicle

The valve assembly, especially for the adjustment of the heating medium/cooling medium flow in a motor vehicle, comprises a first valve component (62), which is adjustable between a first and a second connecting position in dependence upon a pressure difference prevailing between a first and a second line, and a second valve component (78) which changes the flow capacity of the first valve component depending upon temperature. An independent claim is included for the vehicle's heating system incorporating the aforesaid valve assembly.