I haven’t found a way - I get the same response, a AC unit nearby is always about 3-7 degrees higher. I’m going to guess the sensor is ‘calibrated’ at the factory and the Echo just reads the results. Besides soldering & replacing the sensor to hopefully fix the temperature setting, I’d call Amazon, I had an excellent experience with their customer support. You other option is to replace the board itself, maybe trading in your broken board to help lower the price of a new one. There’s a take apart here on ifixit on how to replace the subwoofer; You could use those instructions to take the boards out & replace the one you want. That’s another question; Where is the temperature sensor!