Aqualink indoor controller indicates water temp is 82 degrees, but thermometer in pool is reading 65 degrees. Pool was installed 3 years ago. You can only re-calibrate the water temp settings on the indoor controller by approx. 4 degrees so I feel I have a problem, maybe the water temp sensor? Is there a way to test the sensor? Would a faulty sensor give a high temp reading on the indoor controller? Any help would be appreciated. I hate throwing parts at it.