Pump relay control for each zone options

post by puremtbr on Apr 20, 2020

I bought the 12-zone Rachio 3 from Costco but haven’t installed just yet as I’ve run into a potential issue that I’d like to get feedback on. I have a rust inhibitor injector pump connected to my current system that I’ve programmed to only turn on for 4 of my zones (my current Hunter controller allows the pump to be on/off for each zone). It appears that I can’t control the pump to operate per zone, it’s either all or nothing on the Rachio 3. Based on the cost of the rust inhibitor, this isn’t feasible option for me. After reading numerous posts and suggestions from 2016 to add this feature, I’ve seen some workarounds being developed but I’m not sure if there are any recent ones I’m missing. Here’s what I’ve learned as the options:

1. Add the feature as a future upgrade. This seems to be the simplest option by adding a toggle in the advanced wiring options for each zone. Can someone from Rachio comment if this is on the upgrade plan for the immediate future?
2. There was a workaround someone posted by adding relays to the zone that you don’t want to turn on/off. Unlike the example posted, I have 4 zones that I want the pump on, thus I’ll need 4 relays added to the controller, which is not a very elegant solution.
3. Another option someone posted was a script that can be run to turn on/off the pump, but it needs to be hosted on something that is always on, which I don’t have.
4. Another possible solution is to have the pump on a smart outlet and use IFTTT to turn on/off the pump, but I don’t believe you can choose individual zones to control this action in IFTTT. This would have been a good alternative if individual zone controls were allowed in IFTTT.

Am I missing anything as a viable options or updates on the above before I return this. I was really excited when I picked this up.

post by Stewart on Apr 21, 2020

Maybe something like

powering the pump when any of zones 1-4 are active. You’d use a 24 VDC relay, with the resistor chosen to provide about 24 V to the coil.

post by DLane on Apr 21, 2020

@puremtbr - how many zones do you have in total that will be running?

Two other options are:

1. Use a second controller for the non-injection zones. And no, there is no synchronization between the controllers - one would have to use time or day limits to prevent them from stepping on each other (pulling down the water pressure to the other system).
2. If it is fewer than 4 zones that are non-injection then wire a relay to open the pump line so it won’t start on those zones. The inverse to what @Stewart proposed above and in prior posts.

post by Gene on Apr 22, 2020

One option you may wish to consider, and which may be easier to understand, is to get a timer relay and move the zones which need the rust inhibitor onto a separate schedule within it’s own time slot.

For this you would need something like this:

Terminals 1 & 2 would be connected to 24 V + and - on the Rachio. Terminal 3 would connect to M terminal and your rust inhibitor would connect to terminal 4. This configuration uses this relay as a time of day enable between the Master valve signal and the rust inhibitor. Both the relay and the Master valve need to be active at the same time in order for the rust inhibitor to be dispersed, if either is inactive the system will not trigger the injector.

For example, if you have the zones which require the rust inhibitor all on one schedule to run between 6 and 7AM, you can set the relay to be active between 6 and 7AM. The rest of your zones can be scheduled to start at 7:30 am at which time the relay would have disconnected the rust inhibitor from your system.

post by DLane on Apr 22, 2020

@puremtbr - the relays referenced by @Stewart are DC relays, not AC powered relays. There is also a diode in there to prevent the other zones on the pump circuit from tripping their solenoids when a different zone is running. There is also a resistor and capacitor in the circuit. The wires to the irrigation solenoids would be at the Z1, Z2, etc. location (zone terminals on the Rachio).

post by jrego7 on Apr 26, 2020

The most flexible solution would be to update the firmware to allow for pump control on a schedule basis (not zones). The schedules would allow you to schedule and select any number of zones with pump active/inactive. This scenario would be more flexible than only allowing pump active/inactive on a zone basis.

Example:

Schedule 1 Mon, Wed, Fri Zones 3, 4, 5, 6 /pump active

Schedule 2 Tues, Thur, Sat Zones 1, 2 /pump inactive

In this scenario it allows much greater flexibility to control the pump. Some one like yourself with a rust inhibitor would activate the pump with all schedules. Someone with a fertigation or bug system, doesn’t need to run it with every watering, or every zone but instead at a more flexible schedule. In my opinion it gives the user ultimate control. Make sense?

post by puremtbr on May 12, 2020

Appreciate everyone’s input. While the timer and relay solutions are a workaround, I’m having a hard time justifying the added work and/or upkeep for something that can be implemented so quickly through a software upgrade. I understand others may feel those are viable solutions for them and that’s totally fine, it’s just not for me. I just returned it to Costco and will stay with my existing set-up. I’ll check-in every once in a while to see if anything changes. Thanks again everyone.