Rain sensors conserve water by suspending irrigation during rainfall. They come in a ‘wired’ and ‘wireless’ version and are a requirement if you wish to obtain a watering exemption.
The internals of the rain sensor consists of small wooden discs that swell with moisture and then send a signal to the control box to suspend watering.
To be honest I have heard mixed reports on their effectiveness. Some people report the retic continuing to run even with a rain sensor while others say they work well. As the one installing them I do so but I do not offer a warranty on them for that reason.
Having said that I am sure the technology is improving all the time and they will become more reliable.
For help with any of these issues call Andrew on 0400044236 or email firstname.lastname@example.org