When temperatures reach below 68 degrees it beeps at odd intervals. anywhere from 1 beep every couple hours to 1 beep every 2 minutes for a up to 20 minutes then 1 beep an hour later etc. once the temperature goes up to around 69-70 the beeps stop. Temp. is the only thing I an see being a problem. Could it be something else? Am replacing the batteries in a.m. Should i replace the device?