The first thing to try is to unplug the common wire terminal (so the solenoids will not be activated) and see if the controller still crashes. If not, that means the problem is either a defective solenoid, or the PTC fuse under high temperature (as discussed in this thread: viewtopic.php?f=9&t=84). If the controller still crashes even after the common wire is disconnected, you should return the controller for a replacement. Send email to [email protected] for support.
I’m pretty sure it isn’t a heat problem. It’s consistently under 70F here now, and the controller is in my garage, which is typically cooler than that. Will the defective solenoid show when the controller crashes after a particular zone?