This article explains Rachio's incompatibility with Hunter Solar Sync sensors.
Rachio is NOT affiliated or authorized by HUNTER - the HUNTER brand sensors are manufactured by HUNTER. This article is intended for instructional and compatibility purposes only.
Rachio does not recommend the use of 3rd party sensors unless required by local code. Remember to always enable Weather Intelligence features to skip watering schedules BEFORE it rains; rain sensors will only skip watering schedules AFTER it rains.
The Rachio controllers (Generation 1, Generation 2 & Rachio 3) are NOT compatible with the Hunter Solar Sync as it uses a proprietary connection that will only work with specific Hunter controllers.