Buzzing sound from the controller

I have connected as mentioned in the guide and I tested and named all my zones. It seems they all worked fine except. 1. I can hear a buzzing noise coming out of the main box, 2. I had one extra wire which was not connected to the previous board and 3. I have a wireless Hunter Sync Rain sensor.

Please suggest how to get rid of the sound and also why I had one extra wire unconnected?

@Zia_buet01 - can you post a picture of the wiring? Was a picture taken of the wiring in the previous controller - if so, can that be posted?

Sometimes there is an extra wire in the field wire, say the wire has 7 zone wires and a common wire but only 6 actual zones - in this case there would be an extra wire.

Thanks for your reply. Please see the attached pictures.

@Zia_buet01 - great job on having a before picture.

I think the Hunter Wireless Solar Sync receiver should be hooked up like a basic wired rain sensor - S1 and 24V AC-
See →

I haven’t seen where Rachio has stated they’re compatible with this model of Hunter sensor.

If the unit is still buzzing, take one of the wires out for the Hunter sensor and see if the buzzing stops.

I’m not sure why a spare discrete wire was left unused in this installation. If you have access to a multimeter (AKA volt/ohm meter) then I’d test the resistivity between the unused wire and the common wire. If there is about 30 Ohms of resistivity then there may be another valve out there. If there is infinite resistivity (i.e. an open circuit), then it may just be a spare wire placed in the trench in the event that a wire goes bad somewhere.

I have taken out the sensor but the buzzing sound is still there and after closely monitoring, now I think it is coming from the adapter. If I press hard and hold it it almost goes away.

What type of rain sensor goes with rachio3?

I will check the wire reaistivity later and keep you posted.

Thanks for your help.

@Zia_buet01 - That sensor MAY work with Rachio, they may have not tested it and noted it on their website. It looks like to me it may operate just like a wired sensor. If you want to give it a try, go ahead.

An external sensor is not necessary with Rachio as it will use the internet to get the local weather and not water if it is going to be too windy, raining or too cold (if the options are selected). An external sensor is a belts and suspenders approach for the rain shower (like I had yesterday) that misses the weather station and wasn’t forecasted to be that strong.

Regarding the transformer, you can reach out to Rachio customer support and I’ll bet they’ll send you a replacement.