Hi Carey,
Could you try to insert the sensor again and make sure the soil around it is tight enough. If there is large gap between the soil and sensor, the ai between them could generate large noise.If the problem still remains, please send us email to support@netrohome.com with your Netro account registered email.
For the run off issue, you can add reset time between zones through Settings->Prefrences->Schedulling->Rest time. Please let us know if it works.
Thanks,
Netro Support