I purchased a sensor (Order Number 100306201 - 6 Jan 2018) to replace an outside sensor that went bad after 1 year. I ordered Model No. 00592TX and was sent Model No. 00592TXR (I assume R means Replacement). After receiving the unit, I installed the batteries, checked the battery orientation, checked that the light was flashing, placed the switch in the “A” position (the position in the old sensor), and set it outside for one hour. The temperature reading never varied from 70 degrees F. (The Weather Service said that it was 17 degrees F outside). I brought the unit back in, changed the switch position to “B”, checked the battery orientation, checked that the light was flashing, and set it outside for 1 hour. It was still registering 70 degrees F. I brought it back in, changed the switch to the “C” position, checked the battery orientation, made sure the light was flashing, and set it back outside for 1 hour. It was still registering 70 degrees F outside. Frustrated at this point, I changed the batteries in the inside unit, but the temperature still registered an unchanging 70 degrees. During the last two days the outside temperature has varied from 39 degrees to 16 degrees F, but the reading has remained steady at 70 degrees. Either I have been sent an incompatible unit, or a defective one. Please send me a replacement unit that will work with the Model 75075RX inside unit. Thank you.