Why does the compressor of the air-water heat pump operate despite solar thermal (temperature 140°C)?

I have recently been operating an air-to-water heat pump coupled with solar thermal. I have often noticed that hot water was produced with the compressor of the heat pump instead of with the solar thermal, although 140°C is displayed in the modules. It is a system from Buderus. Does anyone have experience with it?

Hi,

although 140°C is displayed on the modules

Excuse me? 140 °C? Are the things not connected or is the pump not running? Something is seriously wrong there. Who installed that? They should fix it quite quickly.

At these temperatures, the solar thermal modules can also break very quickly.

Best regards,

Andreas