I wanted a little bit of a backup plan since my closest (good) weather station was about 6-7 miles away. I found my Rachio starting to water right after rain storms sometimes. (maybe not enough, I know) I just didn't want to be "that guy" who has their sprinklers running during or shortly after it just rained.
Anyway, added a Rainbird WR2 sensor and installation was pretty easy. Followed the directions for wiring from Rachio. I also went into the app and put a "Rain" sensor on S1.
Problem I'm having now, NO watering works at all. Rachio will act like everything is fine; I can turn zones on manually or let the schedule run, however, NOTHING actually waters. I don't even here a slight click on the zone from the relay(I think I used to hear that), But none the less, no matter what zone I try, no valves open, etc.
I thought ok, maybe I have a bad WR2. Got another one to replace it. Same thing!
If I remove the WR2... things work fine as they did before I added the sensor.