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Impact Sprinkler Trip Pin Not Working | All You Need To Know

An impact sprinkler trip pin may stop working due to misalignment, obstructions, incorrect pressure, or other damaged parts. But you can resolve the problem if you re-adjust the pin, use the correct water pressure, clean the part, or repair/replace any damaged components.

Impact Sprinkler Trip Pin Not Working

If you ask me, I’d say that impact sprinklers are a worthy upgrade over conventional watering systems. With a good impact sprinkler for low pressure, you can water your lawn at any time.

Of course, there are a lot more advantages to using impact sprinkler heads, such as increased versatility and watering range. However, it is a machine, and like any other machine, it can encounter issues at times. And one of the most annoying issues you can encounter is a malfunctioning trip pin.

That’s why I have expanded on this issue here, so read on if you want solutions!

What Is The Impact Sprinkler Trip Pin?

What Is The Impact Sprinkler Trip Pin

If you are not very well-versed in impact sprinkler heads, you might not know what the trip pin is. That is why I have briefly discussed it in this section for your convenience.

A typical impact sprinkler head consists of several parts, such as the impact arm, bearing washer, arm spring, solenoid valve, trip collar, trip pin, and others. If you have ever wondered why sprinklers pulsate, then the answer is the impact arm. Likewise, the trip collar helps in fine-tuning the watering range and so on. Checkout what pulsating sprinklers are in this exclusive article to know more.

In that context, the trip pin is of particular interest because it allows the sprinkler head to oscillate when in use. So, if it stops working or becomes damaged, your impact sprinkler will get fixed in one direction, thereby reducing its usefulness.

The trip pin is usually located at the base of the sprinkler head, just below the trip collar. Under normal circumstances, it is aligned downwards, which helps to rotate the sprinkler. On that note, it works in conjunction with the other moving parts so that your sprinkler can distribute water evenly throughout the garden.

Why Has Your Impact Sprinkler Trip Pin Stopped Working?

In order to fix the problem, you’ll need to identify the cause behind it first. There are several reasons that can cause the trip pin to stop working, as I have discussed below.

1. Misaligned Pin

A misaligned trip pin is the most common and obvious cause of this issue. As I have mentioned before, a trip pin is normally aligned in a downward position. But due to frequent usage or external impacts, the pin might become displaced from its original alignment. This jams the oscillation mechanism, which ultimately causes the sprinkler head to become fixed in a single direction.

2. Incorrect Water Pressure

An impact sprinkler requires a moderately pressurized water flow for normal operations. So, if the water pressure becomes abnormally high or low, then the sprinkler head will not be able to rotate properly.

If the water pressure is considerably higher than the acceptable range, it will strain the trip pin and the trip collar. That will subsequently damage the pin, which will cause the sprinkler head to stop oscillating.

On the other hand, if the water pressure is too low, the stream will not be able to apply enough force on the impact head to rotate it. As a result, the trip pins will not be triggered, which will prevent the sprinkler head from rotating.

3. Obstructions

If any object or debris becomes lodged inside the trip pin (or any other part, for that matter), it will jam the component and prevent it from functioning as expected. In other cases, the foreign object will cause unnecessary friction between the sprinkler parts, which will eventually wear them out. And once that happens, your sprinkler head will stop working.

4. Damaged Parts

I have already stated that the trip pins work in conjunction with other parts of the sprinkler head. So, if any of these components were to become damaged, it would consequently affect the normal functioning of the pin.

How To Restore The Normal Functions Of A Trip Pin?

Based on the underlying reason, there are several ways to fix malfunctioning trip pins. I have discussed each of these solutions in detail below, so keep reading.

1. Adjust The Trip Pins

In case the pin has become misaligned, you can restore its normal functions by simply re-adjusting it back to its original position. The pin can be easily adjusted with the help of a flathead screwdriver. All you need to do is tighten the pin with this screwdriver, and once it is back in proper alignment, the sprinkler head will start to rotate again.


Be careful not to tighten the pin too hard, or else it might break. You will then have to replace the broken pin entirely, which can be a lot more problematic.

2. Ensure The Correct Water Pressure

If the problem is due to unusual water pressures, then you will need to adjust it with the help of a pressure gauge.

Generally, impact sprinklers operate at a pressure of 50 to 60 PSI. However, not all impact sprinklers operate within the same pressure range, so make sure to check the documentation that comes with the product.

When the pressure is above or below the recommended range, you can first try to adjust the pressure of the faucet or tap. If that doesn’t make any difference, you will need to install a pressure regulator at the water source to make the necessary pressure adjustment.

3. Clean The Sprinkler Parts

In case the pin or any other part of the sprinkler has become obstructed with dirt and debris, you should clean them to restore normal functions. If you gently rub the sprinkler parts with sandpaper, you can remove any loose dirt. But if the debris is stuck inside the components, you can flush them out with a spray of water or a cleaning solution.

4. Repair Or Replace The Other Parts Of The Sprinkler

When the problem is due to damages in the impact head, sprinkler valve box, washer, or any other component, then you’ll need to troubleshoot them individually. For instance, if the arm spring has come loose, you can adjust it with needle nose pliers. Or if the impact arm has become bent or damaged, you will need to replace it with a new one.

Lawn water sprinkler spraying water on garden lawn on hot summer day. Automatic watering lawns. Impact Sprinkler Trip Pin Final Words.

Impact Sprinkler Trip Pin Final Words

The problem of a malfunctioning impact sprinkler trip pin can be resolved fairly easily on your own. However, if you are feeling a bit unsure about going the DIY route, you can always seek help from a professional.

In this regard, periodic maintenance can prevent this problem from appearing again. 

Many users have asked me about how many gallons per minute an impact sprinkler uses. And the answer is - quite a lot! That’s why it is important that you have an adequate water supply to handle the load, or else these problems will become frequent.