Use existing temperature sensors solar boiler

My solar boiler has two P1000 ptc’s tot measure the temperature of the solar panel and of the boiler t. ank. I would like to monitor these temperatures in Home Assistant.
One way could be to connect an ESP32 io in parallel to these P1000 resistors. How can I do this without affecting the existing solar boiler controller? I have no information about the electrical diagram of the controller.