Rachio 3 not supplying enough power

I have a Rachio 3 and have hooked it up correctly and cannot get zones to operate. Have contacted Rachio and they have verified that voltage is 26v but milliamps are low - 81. I have 10 zones and no pump or sensors. They suggested to change the advanced wiring on the app from ‘neither’ to ‘well or pump start relay’. This increased the milliamps to 88 but this is still not enough to operate the solenoid valve.

Does anyone know how to increase the milliamps on a Rachio 3 controller?

old Rainbird wiring

Rachio wiring

Volt meter showing 25/26 volts.


What kind of valve are you trying to run? 88 ma should be more than enough to run most any traditional irrigation valve. I see the original controller is an extremely old model. If the valves are equally as old, you may need to replace.

@dm4545 - out of curiosity, what is the resistivity down one zone line and back through the common? I would disconnect at least one end of the circuit from the Rachio to prevent the measurement being impacted by the Rachio.

The ohms were around 50 ohms per zone

You don’t actually increase the current. The current will depend on the applied voltage and the valves resistance. You have 26VAC which is fine. Where did you actually measure that?

50 ohms resistance for a solenoid also seems typical, which would mean the current draw would be about 0.5.amps (500 milliamperes)

Check the voltage from each zone output to common, with your meter probe, when each zone is turned on.

I suspect your common wire is actually connected to one of the zone outputs. Also, if the valves were working on your old Rainbird system then they should still be ok. They won’t all fail at once.

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Also, 85 milliamperes is really low. Sorry if this sounds insulting but remember that for current measurements the meter has to be in series with the circuit so that the current passes through the meter.

I did figure out the the common wire was connected to a zone - even though I connect the wire as per the old controller photo. That’s really weird.

System up and running


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