Idea For Rachio- add on to all brands of controllers

We know Rachio is currently maxed out at 16 zones. Is it possible for Rachio to have expansion modules? I know Skydrop has an expansion module and Hunter Hydrawise too. Another idea would have a way for Rachio could be an add-on to ANY brand of controller (like the ET Water Hermit Crab does, attaching to an existing controller with cable). The only limitation on zones would be the capacity of the host controller. Rachio would just increase zone count in its software. Rachio could then have a huge market or possibly private label for the major manufacturers. I have many ideas, but don’t know if they are possible.

Any comments???


Hey @robertokc!
Thank you for the feedback, we have had more than one user talk about expansion modules. Just wondering, how do you see this working differently than getting another controller? Is another controller more zones than you are wanting to add, or is it more that you want one cohesive system?
The add on to any controller idea is super interesting, I’ve never thought of that… any other benefits you see from that change other than additional zones? Just curious.
McKynzee :rachio:

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The industry is familiar with expansion modules. If you add a second controller, I fear problems with conflicting run times and a total confusion by homeowners. It’s just not a good idea.

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ET Water has their Hermit Crab that connects to all major controllers by a cable that fits the USB pins on each specific controller. The problem with that product is its high cost and very high subscription fee. The add on is programmed on a PC or smartphone app. ET Water uses AccuWeather to estimate ET. The control wires all go to the host controller.

What if we were able to make multiple devices operate as one to avoid overlapping run times? I do like the idea of the expansion modules, but what I’m thinking is that would require developing new hardware. Not that this isn’t an option, but it’s a much longer time frame. If we were able to use multiple controllers and just adjust the way they work together, this would be software development, which would most likely be a shorter time frame.
That ET water product is interesting, but definitely pretty pricey. Also if you don’t have an approved controlled it is super pricey. Other than simplifying installation, what benefits do you see for an attachment for current controllers?

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Sure, if you get multiple controllers to act as one that would be good. However, most residential systems are 16 zones or less. The selling point with that Hermit Crab is one can leave the existing controller without paying a very high price for one of their stand alone controllers. I was just thinking of a way that Rachio could capture the new install market, too. That might not be your marketing model. For replacement market it’s fine the way things are. But when I have asked contractors here in Oklahoma City, they express pushback with a controller without faceplate buttons. Still think Rachio is the best. Things have been quiet about the reviews of Hunters wifi product. I’m skeptical.


This is actually a good idea. ET Water was certainly ahead of the curve with the Hermit Crab. It is limited to the controllers with remote ports unless the panel can be replaced with one of theirs. Not all controllers have remote ports. The subscription fee is a bad idea even though I understand there are costs involved. Customers do not want any more fees.

Using sprinklers is costing them enough as it is, especially if they are using more than they need. I wonder if sprinkler system owners ever thought that the cost of maintaining the system and watering the lawn would cost them so much. It is an on going cost unless the system is just shut off completely.

As for Hunter’s Hydrawise, they also want to charge you a fee for using a personal weather station in the area around your house. You can subscribe to one of the two closest airport weather stations, but you have to be on the Enthusiast plan to get stations closer to your location. No one wants an extra monthly fee.

I do agree that not all end users want to replace the whole panel. The savvy smart controller customers like it, but there are some who like to have access to buttons and a display.

Especially, the new home builder sprinkler companies. They want what is cheapest, easiest, and quickest. The companies use subs and they aren’t necessarily the most knowledable about the latest, greatest, or most efficient. I mean, some subs use VAN nozzles on all the new systems because using fixed arc nozzles means they have to think and look in more than one bag to find the right nozzle!

Sorry about that little rant.

This is a good topic. I like the idea.


Ditto. You speak the truth. I can speak from experience with ET Water. They use AccuWeather and charge outrageous subscription fees for daily ET updates.
I wont say any more on them. Nobody needs to pay subscription fees for weather data anymore.