Do you have the old WMR100 or the WMR100N? If you get the THGN801, it is automatically set on channel 1. If you have the old WMR100 which has the temperature/wind in the same unit, then it will not work. I had the exact same problem, so I bought a new THGN801 and I also bought a new WGR800 wind vane/anemometer. You can find them as low as $70 or $80 online. Once I did this, everything has worked perfectly.