Late last week I started to experience problems with various Z-Wave modules that began having communication problems. One module refused to work at all and others, including our thermostats, demonstrated frequent communication problems.
This was frustrating because I had never experienced communication issues with my Z-Wave gear; it is one of the reasons that I have come to prefer Z-Wave.
At first I thought it was a software issue and then I began checking batteries and routing. After a couple of days I figured out what was actually causing the problem.
Our baby monitors were creating interference. It turns out that the monitors operate in the 900 MHz range and so does Z-Wave. This also explained why it wasn’t my entire Z-Wave network that had problems; only the devices clustered in and near the nursery.
The monitor that we have provides a button to change available channels. Tapping this a few times adjusted the frequency of the monitors enough to remove the interference. Ever since then the communication problems have disappeared (in fact, the change was nearly instant).