Zone Fault notifications started popping up

My 1+ year old Gen2 controller started sending zone fault notifications for all the zones since last week.
I tried the following and still no luck. None of the zones working.

  1. Restarted the controller and tried to do quick run of a zone for 1 minute. Controller restarted
  2. Quick run of any zone is resulting in a restart of the Rachio controller
  3. I removed rain sensor cables. Turned off rain sensor setting in the unit. Tried quick run. Same result as above
  4. I checked for loose cables at the controller. Nothing I found.
  5. I unplugged every cable at the controller and plugged it back in. Then tried quick run. Same result!

I have volt meter. I unplugged power connector from Rachio so that it is off. I set the Multimeter to Ohm setting. Checked the value between Common and Master Valve. Got 0L. I am seeing same result for all the zones. Then I changed the Ohm setting to finer grain (Milli Ohm) on my multi meter. When I measured now, I did see 2-4 milli ohms and it keep fluctuating.

I didn’t have any cable guy work in our yard.
I am out of ideas.

I appreciate help!


Note: I did submit a ticket from the app. Waiting for Rachi tech to look at this and provide suggestions…

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@videoguy - Well the good news is that Rachio has a 2 year warranty.

I would try disconnecting the common wire, all zone wires and the master valve/pump start (if installed) and then perform a quick run on any zone and see what happens.

Next, check the resistance down the wires (not into the Rachio) for the common and the zone wires to see what the resistivity is there.

I’m wondering if it is the power supply that isn’t putting out enough MilliAmps and that is triggering the brownout that causes the zone fault.

With a Gen 2, Rachio logs the amount of power each zone pulls so if that value is updated that could give a clue as to if it is wiring or power supply that may be causing the problem.


Funny though. I just kinda did what you are suggesting before reading this.
I disabled Master Control Valve setting in the app. I didn’t unplug any wires from the controller. Then I did a quick run on a zone. This time the controller didn’t restart. It didn’t pop up zone fault notification. I did the same test in couple of other zones. I don’t see reboots nor zone fault notifications. Water wasn’t output as master valve is disabled. But the good thing is that it is not reporting the zone fault any more.
While a quick run is in progress, I measured voltage on that zone at the controller between zone wire and common wire. I saw 27V which is expected value.

I enabled Master valve in the app and tried a quick run on a zone. The zone fault issue came back.
I have 16 zone system with 6 unused zones. Then I enabled one of those unused zones (Zone 11). As it is unused, no zone wire was plugged into the controller. Then I did quick run on this zone. The zone fault is back. It looks like there is an issue when Master valve is being powered on.

Thanks @DLane!


I don’t know why this post was marked as solved.
It is not. With Master control valve on, I am still getting zone faults.

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@videoguy - Now that the error domain has been reduced to the master valve, here is what I’d try.

Move the Master Valve wire to zone 11 and run zone 11 manually. If there is a wire fault reported on zone 11 (my bet) then there is something up with the wiring to the master valve.

If there isn’t a wiring fault reported above, then I’d take a zone wire from a zone that didn’t fault when the master valve was disabled and place it in the master valve terminal, with the master valve setting turned on in the application and perform a quick run on that zone (only one wire actually being energized as that terminal will be empty as its wire is in the master valve terminal. If a wire fault shows up in this configuration, then I’d call Rachio as there may be something up with the unit.

However, I think fire ants, squirrels or rats may have chewed on the wires going to the master valve causing a short. I have seen fire ants all over electrical connections before - something about it attracts them. It could also be the actual master valve solenoid that may have shorted out.

In the mean time you could leave the master valve manually open to run the system (without the master valve activated in the app) until you get it fixed.


Thanks @DLane !
I am able to fix it. It turns out to be bad solenoid. I replaced it and now my zones are live and no zone fault notifications from Rachio! To get there, I did lot of troubleshooting. Adding those notes below for anyone researching zone faults in future.
I borrowed new power supply from neighbor’s Rachio. I still got zone faults with this power supply. So power supply is ruled out.
Then I went to Home Depot, bought two Hunter PGP inline valves and sprinkler wire. Connected one of them to Rachio master port. Other one to zone 11. Connected common port to both the valve’s common port. Then I ran zone 11. I heard clicks from both the valves and Rachio didn’t restart nor did it popup zone fault. That told me controller is not problem. It is outside in the yard.
I went back to Home Depot and bought three different types of solenoids (rainbird, hunter and orbit). Then came back and started locating valve boxes. This part took a while. I took a Philips screw driver and started poking in the ground. I found a valve box close to valve box that houses all the wiring before it goes to sprinkler controller. That turned out to be one of the zones. It is not master valve.

After 20 minutes of frantic poking in the front yard starting from city water line, I found another valve box located below front shrubs.

I turned the knob 90 degrees on the back flow preventor (I think) so that water doesn’t come to main valve. Then I completely unscrewed the solenoid. Then water started gushing out and started hitting up 3-4 ft high. The damn back flow preventor has two knobs. I didn’t realize I had to turn both of them off. Once done, flooding from master valve came under control.

Spent 10-15 minutes draining water from the valve box. Once the solenoid inlet is visible, I disconnected old one and connected new one.

Then Ran a zone. Controller didn’t report zone fault. That was great sign. Then opened the water line partially to sprinkler system. Then ran a zone. Bingo! The zone sprinkler heads popped up and started watering. Repeated this on couple of zones. Everything seemed to be working fine now.

I am rerunning the schedules that were skipped last week.
Had I called a irrigation pro, I probably would have paid $200-300. In the end, It is $8 solenoid and $5 waterproof wire nuts for parts and time I spent troubleshooting this.

Conclusion: Rachio saved the day. It is the best sprinkler controller! Period.


@DLane :champagne: