Thank you for the reply.I have the Pentair Solartouch controller works very well. It shuts down flow to the panels when a cloud comes over, also puts pump into low speed when solar is not available or viable.
My panels/sensor is roughly 75 feet from the controller, i haven't noticed any problems with probe readings, but if I want I can recalibrate the sensors. When the rooftop sensors reads 40+ C temp rise thru the panels is roughly 5 C. I have a laser temp reader.
Is this the controller you have?