Can you provide some details about your setup? For example, what type of AC transformer do you have? Are you using a WiFi dongle or wired Ethernet connection? Have you set up a sprinkler program and if so does it open multiple valves at the same time?
Thanks for your quick reply. I had it running of separate power all night and did not see it disconnect from the switch. I have now swapped the power back to the sprinkler board supplying it and I will monitor today and see if it does drop.
I purchased the kit and the power supply from your Australian reseller, OpenLab. It looked like the transformer was suggested on their site. http://openlab.com.au/shop/24-volt-ac-mains-adapter/
I am using wired ethernet and am using the mobile default application (ip/sprinklers) and previously I had no more than 2 valves open at once for testing, but in day to day usage I can’t use more than 1 at a time as the water pump can’t handle two runs on at once. The first day I had it running, it could open two valves at once with no issues that I could see. The raspberrypi is rebooting even while no valves are open.
I believe the constant random rebootings have corrupted something to do with the program, so I will reinstall your supplied sd image today and test further for stability.