New Install - Master Fault Error

Troubleshooting
1

I just replaced my Hunter box with the Rachio 3. Our system uses a pump from the lake so I set the “M” Terminal for Well or Pump Start Relay.

When I try to run the system, I get a message in the app that says, “Master valve may have wiring issue and cannot water until fixed.” I also get an email alert that Rachio detected a fault in zone master valve.

As far as I can tell, everything is wired correctly. Looking at troubleshooting steps from other posts, I tried removing the M and 1 wires and starting the system with Zone 1 and got no error. Also no error with M removed and 1 attached. But as soon as the M wire is attached, I get the error again.

[Edit: I tried the system with eveything plugged in and Zone 1 worked without error. However, when I tried to run Zone 2, the error returned and remains no matter what zone I try again.]

The only thing I can think of is that I have two wires running to the C and it was very hard to get both in to the Rachio. The Hunter was a screw-based wire system so there was no issue.

I am attaching photos of the old wiring on the Hunter vs the Rachio. If anyone can help I’d appreciate it.

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2

@davpel - Two comments:

  1. One can move the white common wire to the other C terminal after zone 8. Both C terminals are the same.

  2. What make/model of pump start relay is in use? I think that pump start relay is pulling too much power and it may need to be swapped out with a different one.

1 Like
3

Thanks for the suggestion regarding the other C terminal. I did move it with no luck.

I’ll have to check and find out the make/model of the relay. We just moved into this house and I have no idea where that is.

4

@davpel - I would not expect moving the white wire to the other terminal would have eliminated the master valve error - just making it easier to get the wires in and out with one wire per terminal.

I would look near the pump for the pump start relay as that way the AC lines running to the pump are short. Having a long 24 VAC line to trigger the pump start relay is not a problem. If you have a mult-meter, I’d check the resistivity down pump start relay line and back on the common wire.

I’ve recommended the Orbit pump start relay available from Lowe’s or Home Depot → https://www.homedepot.com/p/Orbit-1-2-HP-Pump-Start-Relay-57009/100181554 and that seems to work for folks. Looks like it is an order and wait at both of my stores, so maybe Amazon for quicker delivery?

5

Thanks. I’ll talk to my sprinkler guy about doing this.