If you’ve disconnected the sensor you still need that little jumper that was in both sensor terminals at first purchase (or a makeshift one if you don’t have it anymore). You could try a factory reset by putting the timer into off mode and holding down the reset button for about 10 seconds (until your screen display shows everything at once). you could also try deauthorizing your device and re-pairing it. If you have any further issues after that please contact our product support tam either by email or phone.