Stumped on Retrofit

Recently purchased a home and am completely stumped with existing install.

Inspector should have tested the system- but didn’t. :-/ I was too overwhelmed at the time with other responsibilities to realize. But, such is life. So, time for some DIY!

It’s a combination of an Orbit 27896, an RIB24P relay, Flotec FP5172-08 1.5HP compressor and what looks like 7 zones.

Following the instructions for the orbit to manually water I can’t seem to get it running. The light on the relay never turns on, and compressor never begins to run.

So, I’m assuming this is an issue with the relay, the compressor or both. Shouldn’t be a water issue as the hose works just fine on the other side of the shed. Could the irrigation control valve connections be the culprit?

I bought the Rachio 3 before I even touched the thing but now am concerned about hooking it up to this if there’s a fault of some kind.

My guess is the relay will stay in the system as it’s turn on for the compressor rather than powering the sprinkler controller?

Can someone walk me through some troubleshooting steps? I’d like to narrow down what’s working and what’s not.

I’m handy with a multimeter and can do basic electrical work (not an electrician but a hobbyist). This is my first time dealing with a sprinkler system however and it’s not registering how this should all work together.

Pictures below.

Hope they are visible / not auto-resized by the forum.

PS there was a small sheet of instructions left presumably by the initial installer of how to turn the system on manually, which I followed, so I can safely assume I am not making a complete blunder and am using the sprinkler controller correctly.

@Holemaker - finally a good install problem for @Gene and me to dive into!

First off some terminology - the RIB24P is a pump start relay (PSR). The Flotec FP5172-08 is a water pump.

Lets make sure the existing system work before ripping out the Orbit system and replacing it with the Rachio (which will be simple once the existing system works).

I’m a little concerned that the RIB24P’s LED isn’t on. It looks like the two white wires from the RIB24P go to the COM and PUMP terminals. When the Orbit system is calling for water there should be 24 VAC across those terminals. If there is not 24 VAC across those terminals see if there is 24 VAC across the 24 VAC Out terminals.

The Orbit system is plugged in and has power right? Any indicators on the front of it to verify?

Here is the wiring diagram for the PIB24P30 ->

We’ll need to know if the Flotec is wired for 120 or 220 VAC.

The way I read the schematic the gray and blue wires should be capped off like they are. Purple and Yellow should take the wires from the circuit breaker panel and Orange and Brown should connect to the wires going to the pump (the pairs could be reversed - circuit breaker/pump and it will work). So I think that wiring looks correct - I’d put a wire nut on that exposed connection.

What is the voltage potential across the Purple and Yellow wires (be careful)? Checking to see that there is power available and if it is 120 or 220V.

Post replies and I think @Gene and I will give it a crack. The first thing is lets make sure there is power everywhere (pump and controller). Then it will be the pump start relay.


Between Yellow and Purple is 240VAC

Compressor says it’s prewired for 230V

I hit enter twice to go manual all zones on the orbit and nothing happens.

Orbit is getting power I had just flipped the breaker since I was in the middle of troubleshooting on my own.

The electrical wires will all have caps etc., was just me poking around.

Also yes the white wires from the relay go to com and pump.

They are referenced as the COM/24VAC coil input wires on the relay.

The yellow wires are the other 2 COM/24VAC


Followed this video:

And it just doesn’t run or indicate anything is running. The zones don’t begin to blink or show any kind of activity. Just kind of defaults back to home screen. Relay never lights up.

So, the relay is likely bad.

But if the compressor is bad, couldn’t that kill the relay and then getting a new relay will fail just the same? Or is there something I misunderstand.


Thanks you’re lifesavers!

Great active forum community here.

I’d rather spend the extra $$ on rachio / automation tech. than crummy contractors!

@Holemaker, welcome to the community, I see @DLane has already got us started on the right track and with the good info.

Relays like these do not usually fail to activate a status LED in case the output has an issue. If your compressor was blown to the point of effecting the relay, the input side should not be effected and you could potentially try again with the unused second output (Brown / Purple wires). I’m a little confused as to what the brown wire is attached to and what function it currently serves, but that is a discussion for a later time. Lets figure out why your relay is inactive.

In case your controller is getting power, I would try disconnecting the relay (two white wires) from the Com / Pump terminals and hook them up to the 24VAC out terminals, for an added safety, you may wish to do so while the controller is unplugged from the power. Should the relay turn on while hooked up to the 24VAC terminals, I would simply proceed with the retrofit and swap out the controller. Since you’ve mentioned that screen goes back to default home screen instead of intermittently showing a manually activated zone(s), it may be that your commands were not interpreted correctly.

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Thanks @Gene

The blue and grey wires are capped off and correspond to unused relay output wires.

See the info here:

The brown wire is connected to the white wire. The colors may not be so clear in the photo.

My guess is 2x 120V to get 240V?

I will try your suggestion in about a half hour when I’m back.

You are right, both outputs are used, this does not change my recommendation, just invalidates my thinking that you’ve had an unused output still available.

In hindsight both outputs were used for safety, either one would turn off the load, but disconnecting both phases makes sure there is no stray 120VAC going to the seemingly turned off pump.

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@Holemaker - Right now my error domain is:

  1. 24 VAC coming out of the Orbit.
  2. RIB24P30 Pump Start Relay.
  3. Flotec pump.

To test for item 1 - use an open safety pin, needle or straight pin, to get to the copper wire on the white COM and Pump wires - use the multimeter to measure voltage potential across those. If there is no 24 VAC when a zone is running that could be the issue. One can also measure the voltage potential across the 24 VAC out terminals and if there is 24 VAC there then connect the RIB24P30 directly to those to see if the LED lights up and the pump runs. Don’t leave it connect long as it will always be running the pump.

To test for item 2 or 3 - turn off the circuit breaker for the pump and directly connect the pump to the input wires. Then turn on the circuit breaker - again don’t let it run long. If there is 24 VAC from the Orbit and the pump runs when directly connected it is probably the RIB24P30. If the pump doesn’t run, then it is the pump.

My $0.02. Your mileage may vary. …


@Gene suggestion was successful! (Partially)

Hooking up relay to 24VAC outputs turned on the relay, light activated and compressor turned on!

So, what does that mean exactly?

But… not so fast. New issue: Sprinklers did not release water.

Wondering if I have to run a hose to this thing?

The original instructions said to be sure the water is turned on on the west side of the shed (compressor on the east). That valve is on and I can get water out of the hose, but nothing from the sprinklers.

I read in the home documents there was a change at some point to move the water from well to city service. Not sure if that’s relevant but figured I’d mention it.

Here’s what it looks like:

Edit: read @DLane suggestions, are these still relevant considering my discovery?

Curious, can you take a picture of the valve box (under the green cover within your last picture). You clearly have an indexing valve connected to the pump, but since no water has came out anywhere, I wonder if it is used at all after conversion to city water.

At point I’m comfortable with recommending to switch over to Rachio, troubleshooting / checking the system is much easier with the modern interface and at this point we know the more complicated parts of the system are working.

If the weather is good, you can do a quick (temporary) conversion instead of the full install. Simply hook up the wires and test the system, be sure to do a full install or take your Rachio indoors after the testing is done.

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@Holemaker - disregard my earlier error domain analysis. I think there are other valves in the system as there are wires connected to the Orbit and an indexing valve doesn’t have wires connected to it. I’d ignore the pump and the indexing valve.

Check to see that water is turned on in the system. One can do that by opening a set screw on the top of individual zone valves. Many times there is a cut off valve for the sprinkler system. If water comes out of the sprinklers in a zone when the manual set screw is opened, then the water is on to the system and we’re probably down to a wiring or configuration issue.

I’d also remove the two white wires that go to the pump relay. In the valve box I’d also check out the wiring for the common wire. Many times, white is the field common wire. In the first picture there is a brown wire in the common terminal and the white wire is in a zone wire. It could be correct. See if water comes out when zone 2 is activated and no other zones.



Wait, if the orbit is the problem, wouldn’t it not engage the zones even though the pump is getting power?

When I removed the orbit, funny that it seems a bunch of lizards / geckos laid eggs in there. It sounded like maracas when I shook them all out. Perhaps that’s a big part of the problem.

Also, how do I handle the COM (brown from irrigation control and white wire fro relay) and Pump

Since you said proceed with the retrofit if that turned on the pump, I pulled the orbit and have begun setting up the “

Interestingly, in the Rachio support article it states:

“In order to avoid potential damage from electrical interference, relays should be installed at least 15 feet away from the Rachio 3.”

Here’s where I am presently:

Funny that my relay is about 2cm away. Is this a big problem? Can I wrap it in mu-metal or copper tape like that used in a guitar to prevent pickup interference?

Here’s the irrigation control photo you requested:

Sorry it’s a bit of a rats nest.


Rachio 3 installed temporarily.

24V wires between COM and M

Rachio turns on the compressor with no issues, but no zones have water.

What I assume to the release valve (red spigot on previous photo) does not release water when I open it up, so assuming this is a water flow problem.

Can I hook up a sprinkler hose from somewhere I know I get water directly to the pump system to see if that will work?


All zones no water.

Can you clarify when you mean by the manual screw and where it’s located?

Some of your commentary / lexicon is going over my head.

I also have a spigot in the system which I presume will tell me if I’m getting water in the system?

That spigot released no water whether pump is on or not.

PS it appears the brown wire is common as it’s bonded to multiple wires in the irrigation control box.

My novice assumption is that there might be a pipe problem between the water on the west side of the shed and the other side as the hose on the west side works fine, while the spigot on the east side after the compressor releases nothing when everything is on.

@DLane was referring to the individual solenoids (like these) on top of the valves in the ground. If you refer to the closeup of the valve box you’ve posted earlier, you’ll notice that one of the solenoids has instructions to turn it counter clockwise 1/4 of a turn in order to turn that individual valve on, turning it counter clockwise until it stops will turn it off. For testing I would pick the right most solenoid, the one that sticks out from the dirt and give it a turn. No power / control signal is necessary as it is a manual override. Be sure not to turn the solenoid more than 1/2 a turn as it would introduce a leak within the valve box and make everything… messy.

Lets see if there is a water in those valves. Look for any other valves, similar to the one controlling the spigot on the west side of the ahead. My guess is that you no longer need to run the pump, as it was used for the well, especially of the spigot right after the motor fails to dispense water even while the pump is running.


@Holemaker - what @Gene said. And forget about the pump start relay, pump, and spigot - they have been abandoned in place. There could be a valve or cutoff before the sprinkler system. Let’s make sure there is water pressure in the sprinkler system.


I understand this as turning the Rachio off?

I’ll try first thing tomorrow.

Thanks again. Have been up to my eyeballs in all kinds of this sort of thing with other aspects of the home. I have DIY in my blood… can’t help screwing around with just about everything, so I’m overjoyed to have some help on the sprinkler side of things where it’s all Greek to me. You guys have really been exceptionally helpful.

Also, don’t understand why the irrigation control box doesn’t have some kind of protection in place to keep all the dirt and junk out. Thinking about going at it with a shop vac but is there some better more permanent solution to this I’m overlooking?

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