So we have arrived at the point where one of your zones is not watering when it is programmed to do so.
We need to determine first if we are working with a Software or Hardware issue.
The best way to determine this is try and run zone in question Manually.
If it runs manually its safe to say Your Wiring and Hardware are working properly and you can skip to the Software section. If your zone still did not come on, then we can skip down to the Hardware section.
Let's start by checking the Water History by navigating to Settings > System > Water History.
Here we can check to see if a Restriction or Setting is preventing the unit from watering.
If we have no Restrictions/Settings preventing the watering next step would be to Power Cycle or even delete and re add your programs.
If your programs are still having trouble running then it may be necessary to Factory Reset your controller.
Hardware issues are the hardest to track down, but with a few simple steps we should be able to pin point the problem.
First thing you want to do is to swap the non working zone with a working zone.
Example 1: Zone 3 is not working.
We swap Zone 3 and Zone 4, and afterwards Zone 4 is not working.
By process of elimination we can determine that the issue lies in the Wiring to Zone 4 or the Valve on Zone 4.
Example 2: Zone 3 is not working.
We swap Zone 3 and Zone 4, and afterwards Zone 3 is still not working.
At this point we would want to use a volt meter to test Zone 3 while activated to confirm the RainMachine Zone 3 is no longer supplying power. In this case you would need to contact RainMachine Support.
Another issue that may arise is if more then 1 zone has stopped working.
In this case you would want to take a close look at your "Common" wire. If there was a break in the wire, all the units down stream of the break would not have a completed circuit and would not work.