Just moved into our home. Existing rachio gen 2 system with 4 active zones. One of my zones won’t turn on via the app. I found the buried box with the green lid. I’m able to turn on that zone two ways: (1) turning the physical valve mechanism (I don’t know the correct terminology) and (2) turning what looks like the electrical valve system. The wires connecting to the various electrical valves were fully exposed, which seemed potentially bad. I sealed connections with wirenuts and PVC glue before I even got the rachio app (this was day one of being in our home, and I wasn’t familiar with how everything worked). I’ve seen on the forums that tech support can access some diagnostics not available in the app. Wondering if I could get some help troubleshooting. Is the solonoid broken if the electrical valve works when I turn it? Is it the connection? Do I need to strip the wires, reconnect them, test, and then reseal them? I’d rather not have them exposed like they were when we moved in.
In other words, the app says the zone turned on, but no water is coming out? If so, it sounds likely to be an electrical issue. Certainly a solenoid may go bad, it sounds more likely to be the wires. I would probably start with the exposed wires, starting with clean wires, and a waterproof wire nut. I tend to test things with a multimeter as well. So, if you have one, maybe clean the wires and turn on the zone, then test the voltage of the wires before doing the wire nuts.
That’s correct, the app thinks it’s running, but they aren’t. I’ll have to look more closely, but I believe the only exposed portion of the wires that I would use to measure voltage are now covered in PVC glue and wire nuts. If so, I’ll have to probably strip them again and test them that way. I’ll give that a shot.
Sounds great, please let us know
I’m with @Thomas_Lerman thinking it is electrical. Since you can manually turn on at the valve by either turning the solenoid or the bleed screw, that tells me that mechanically, the valve is fine. It could be the wiring, or it could be the actual solenoid on top of the valve.
K, when activating the solenoid associated with the non-functional zone (zone 4), I hear clicking. It also doesn’t appear to be the connection. I turned off the water, swapped an adjacent, working solenoid (from zone 3), activated the zone, and sure enough, zone 4 started watering. I’m fairly certain the solenoid for zone 4 is broken. I ordered a replacement and will test it out. We’ll see if that resolves the issue.
Well, it wasn’t the solenoid. It was a misaligned diaphragm in the valve itself. After replacing the solenoid, it didn’t work. So I tried moving the zone wire on the sprinkler control panel to another zone and activating it thru zone 5, thinking perhaps zone 4’s power output might have been reduced from being fried or something. No luck. Tried swapping solenoids again (new one installed at this point), but this time I couldn’t activate zone 4, which was new. So I disassembled the valve and found the pressure releasing mechanism was twisted. After realigning it, zone 4 activated. I’ve ordered a replacement diaphragm for when this one inevitably bites the dust. I now know more than I ever wanted to about how my sprinklers work 
Good diagnostic skills and work in getting it all working!!!