Nobø el-kassett - Vann Varmepump : Kontroll og service

I recently purchased house and i see that previous owner was using Nobø el-kassett - Vann Varmepump, he informs me that this works as it should be but as i can see the system itself is old. refer picture for more clarity i need some technical expert to have a look and advice for safety precautions as follows Use this device or not? Can i change only the control panel with more digital? Now it is consuming 40AMS for this, if i change the device does it require less power? How to regulate the temperature and control)