Richdel 476PRi to Rachio 3 Wiring - HELP!

I am trying to upgrade from an old Richdel to Rachio 3 controller. The old wiring does not make any sense to me after I took the old controller off.

Old Controller: Richdel 476PRi
New Controller: Rachio 3
No of Zones: 4

Old Wiring with Controller:

Old Wiring w/o Controller:
This one probably explains the mess better.

Old Controller wiring Diagram:

@Gene @DLane Help!!

Disregard the thick “2nd cable from outside”, it very much looks like a 24v power cable (use Rachio supply instead).
The cable with two yellow, white and blue cable is a wireless rain sensor, disconnect it from the others and hook it up to appropriate terminals (if you wish), here is more info on that:

Finally, what you primarily interested in is the “First cable from outside”. White wire from that cable goes to any of the C terminals on Rachio, while others are attached to any available numbered terminal. During the setup, you’ll be able to identify, photograph and name a zone, so which wire goes where does not really matter (besides white).

It doesn’t look like you have a master valve, so indicate as such during the setup.

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I am glad you included the last image as I was finding it a little difficult to find the manual. It looks like the terminals are as follows, starting from the left:

  1. 24VAC input - braided white & yellow wires (rain sensor power)
  2. " - braided white & yellow wires (rain sensor power)
  3. Zone 1 - braided white (2nd cable)
  4. Zone 2 - brown (1st cable)
  5. Zone 3 - red (1st cable)
  6. Zone 4 - orange (1st cable)
  7. Zone 5 - N/C
  8. Zone 6 - N/C
  9. Master Valve / Pump Start Relay - N/C
  10. Common - red (unknown), black (unknown), & white (rain sensor)

Wire Nut:

  1. Blue (rain sensor)
  2. White (1st cable)
  3. Braided white (2nd cable)


  • Zone 1 (from old 3) - braided white (2nd cable)
  • Zone 2 (from old 4) - brown (1st cable)
  • Zone 3 (from old 5) - red (1st cable)
  • Zone 4 (from old 6) - orange (1st cable)
  • Common - white (1st cable) & braided white (2nd cable)

To connect the rain sensor (if you wish, may or may not need it depending on how close & accurate weather stations are), I will try this (not 100% positive on some of this, but getting the information from: How do I install a rain sensor? (Generation 2) (

  1. SP - yellow wire (rain sensor)
  2. SC - yellow & white wires (rain sensor)
  3. S1 - blue (rain sensor)
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Thank you @Gene & @Thomas_Lerman for your responses. I don’t want to use the Rain sensor, so without that, this is how I understood your instructions. Is that the correct wiring?

Thanks again for your help!

Disconnect 3 (thick white pair) all together, you don’t need it.

@Gene you mean the white wire labeled as 3? I have 4 zones in total, if I remove that, I will have 3 zones connected i.e. 4,5 &6, no?

Ah, you are right, I mistook it for the power cable. Hook the other side to the C terminal if you can.

You may need to use section of a thin, unused, wire with a wirenut to attach the cable to the Commons.


I agree with @Gene, as you noticed, one of the 2nd cable was connected to zone 1 and the other to common (through the wire nut). All four zones should work with that configuration.

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@Gene @Thomas_Lerman thank you for your help! I followed your instructions for the last white pair and was able to manually test all 4 zones!!!.. looks like we’re back in business!!

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Good work! Please feel free to ask more questions as they come up.

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