My wiring must be wrong after switching from Hunter system

I just recently switched from a Hunter Pro-C to Rachio. The Hunter had a separate rain sensor which I do not plan to use. The Hunter system was working before I swapped out the controllers. However the Rachio does not turn on any of the sprinklers.

I am including a picture of the old unit which has a white wire going to the MV/P terminal. I tried putting this white wire into the Rachio C and then the MV terminals but neither worked.

Does anyone have any theories where I might be going wrong?

Thank you!


It looks like you have a pump or master valve? Did you configure that within the app? I do not see the common wire in the photos.

Yes I tried adjusting the settings in the app. I don’t understand how they did not have a common wire with the old system.

In the first picture, I see an orange wire but cannot see where it is going. Was it hooked to anything?

If you go to your zone valve box(s), what color wire is tied to all the solenoids? One of each color should go to one of the wires on the individual valves, and one (usually white) goes to a big wire nut with ALL the other solenoid wires tied together.

Also, what sensor did you have on the Hunter? Some sensors can be wired in-line with the common, but I’m still not understanding how it doesn’t feed back to the common port. If you have it tied into Rachio, try removing it from the system.

VERY strange that the Hunter worked with no common wire. Honestly, make zero sense.

@jsquires80 - the common wire is the bottom white wire in the Hunter photograph. The labeling on the Hunter is off. Count down the terminals and match them with the labelling, starting with zone 4. There is no master valve in this set up.

It appears that there is a wireless rain sensor installed. Was it connected to the Rachio? If so, I’d try to get the Rachio working first without the rain sensor and then add the rain sensor.

If there are still problems, please post a picture of the Rachio wiring.

Curious if it is labeled wrong. I thought the common terminal was elsewhere, not visible in these photos, according to the manuals. It sounded like it does have a pump or master valve to me. How do you know it is labeled wrong?

Common terminal is on the first picture, shown as unused… (it’s to the left of the SENS terminals).
Below 1st terminal is Master Valve, as per page 11 of the manual.
At this point, it would be helpful to open up the valve box and take a few photos on what is going on there.

Edit: The one way this setup makes sense is that original installer run out of wires and reused the sensor wire to bring commons out to the field. Try using the white from Sensor in the common (and try blue if white doesn’t work). The cable is likely cut somewhere and reused to hookup commons.
Unfortunately, if this ends up working, you’ll not be able to use sensor with Rachio without running a new common wire.