One irrigation head dead. Low pressure?

I noticed today one of six hunter I-20 rotor heads in my #2 zone doesn’t seem to have enough presure to keep itself raised as well as spray/rotate. It was fine last year and I think the irrigation company missed it when opening the system this spring.

If I use the Hunter key to turn off the spray it has enough pressure to raise the shaft. If I turn on the spray it stays in the ground and water coming out of the nozzle gurgles up around the shaft.

All other zones have six I-20 heads and have no issues.

Any quick thoughts on what to check for?

This one sits inside a flower/shrub bed and shoots out into the grass if you’re wondering why there’s no darn grass right around it. :slight_smile:

I would check the house water meter when only zone 2 is operational. If you are seeing a large flow reading, you may have a pipe burst somewhere underground. Gurgling (bubbling) heads should not be sufficient to decrease the pressure to the point that the sprinkler does not extend.

You could also try manually unscrewing the zone 2 solenoid. This may clear out the valve and allow it to open up fully (if it has trouble doing so).


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No water meter, on a well.

Some debris (sand, etc) may have gotten into that one sprinkler and is clogging it up. I’d remove it, swap it with another and see what happens. If it does the same thing in it’s new location, then it’s that sprinkler. At least it will help narrow down where the problem is.

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Where is the rotor on the row of rotors? The end of the row or the middle?

Dig the fitting up under the head to see if it’s connected to flexible piping. If so, dig it back and check for a crimp in the line. If not, check the fittings up to the head to make sure no debris is stuck at one of the fittings. A crimp or debris in the line will block the flow causing this scenario.

A leak will cause this too, but if that is the case you will see water bubbling out of the ground or a turf water bubble.

Let us know what you find.


I believe it is the last sprinkler on the zone from its location relative to the control box. I’m still learning the details of this system as it came with the home we purchased last year.

If I pull the neck up while the zone is on it spits out a small 3’ spray and tries to rotate, but then slowly collapses back into the ground in about 5 seconds. Closing the spray adjuster all the way allows it to extend as in the photo and then no water bubbles up from beneath. I suspect the bubbling when it is not extended is what little water is coming out of the nozzle making its way to the surface.

It looks like I have some digging to do. :slight_smile: Thankfully this head isn’t as sunken as the others and should be easy to get to.

On an unrelated question, is it possible to pop off the plastic cap of the Hunter rotors to clean the adjustment fittings? Some of these heads feel so full of dirt you cannot get the key to mate with the arc or spray adjusters on the inside. I’ve seen how to remove the guts to replace the o-ring inside, but never seen someone take the actual cap off. For example I know you can buy the purple capped units from Hunter for reclaimed water identification. I’d just be looking to pop off the purple cap part and clean out the area beneath it.

@scorp508 I’ve worked on several spray heads recently that had the blue cobra connector on them. The ones that would not come up were crimped.

When you are closing the “spray adjuster” on yours it builds pressure inside the head and the turret extends. When you open it, the pressure is relieved and the turret lowers back into the rotor body. I think there is a crimp or blockage before the head. It’s also possible for a tree root to compress the line.

Regarding the top rubber cap: They will come off, but doesn’t go back on very easy, if at all. And I don’t think they are meant to be replaced. I’ve never replaced one anyway.

Dirt is certainly a problem in the adjustment holes on older heads or ones that retract down into the dirt. You may try flushing the holes with a stream of water from a spray bottle to clean them out. But remember, if the heads are low already, they will get dirt in them again.

Have fun!

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Yes, sand and grit is a real problem. Tell me about your filtration off the well. Suggest at least a 200 mesh filter. Check out Lakos for filtration. scrubver valves are a good prevention too. All the major manufacturers have scrubber valves.

That will be easy. There is none for the irrigation. :open_mouth: The irrigation feed branches off after the pressure tank and before the acid neutralizer. There is a particulate filter after the neutralizer. We are in the process of having the water re-analyzed and may be installing a softener and some other stuff. This may be a good time to give the irrigation feed some love too.

Most people with wells here use a Lakos Sandmaster filter.

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