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Irrigation Systems Repair

Many irrigation system repairs are quite simple and can easily be accomplished by people of average manual dexterity. Other repairs will likely require professional assistance for all by the most experienced and best-equipped do-it-yourselfer.

If you are unsure about the nature of the repair or how to proceed it is probably best to contact a professional irrigation system installer/repairman.

Below are some basic instructions for some of the most common repairs required for standard irrigation systems.

Replace a Broken Head

If you are over-zealous with your lawnmower or you have a football team practicing in your backyard, broken sprinkler heads will be a common problem. A broken head is usually easy to detect because when the system is turned on, water will shoot up like a geyser from the broken head.

Sprinkler heads are usually threaded and screw into a connection buried in the ground as part of the pipe network. To remove the broken head, turn the system off and unscrew the sprinkler head.

Place a flag or a stick into the hole where the head was to mark the location. Take the broken head with you when you buy a new one to make sure you get something compatible.

My sprinkler heads aren’t working right. I have dry spots, but I’ve checked the spacing between heads and it is correct.

These suggestions assume the sprinkler system design is correct, that is the spacing between sprinklers is head-to-head, the pipes are the right size, valve is the right size, etc.

  1. Make sure the radius adjustment screw in the top of each nozzle is turned to the full open position.
  2. Remove one of the nozzles. Most sprinklers have a screen installed under the nozzle. Remove the screen. Is it dirty?
  3. Look at the bottom of the nozzle. Is the small round inlet hole blocked by anything?
  4. If you found dirt in the screen or nozzle you should flush out the pipes again. 90% of the time this problem has been caused by dirt left in the pipes that then clogged the heads. See the next question for how to flush out the pipes.
  5. Check for anything that could be blocking the flow through the sprinklers. Maybe they had a manufacturing problem. I’ve experienced this from time to time with almost every company’s products. A plastic mold gets out of adjustment at the factory and leaves a glob of plastic in the wrong place. Yes, they should catch it at the factory!

My pop-up sprinkler heads keep sticking in the up position. What can I do?

If you are using the little sprinklers that don’t have a retraction spring, this is normal. They pretty much stick up no matter what.

You should replace them with a spring loaded pop-up with a pop-up height of at least 3″, I recommend you use a 4″ pop-up if possible.

Now if you do have spring loaded pop-ups the problem is most likely caused by a small grain of sand, a stick, or something similar in the wiper seal. Here are a few things to try:

  • Put on swimsuit or rain gear and waterproof shoes. Turn on sprinklers. Place your foot on the top of the problem sprinkler and gently but firmly press the riser straight down into the body. Do this several times to dislodge whatever is stuck in the wiper seal. This should correct the problem.
  • If the procedure above works, but a short time later the sprinkler once again starts sticking up it means you have dirt in the pipes. Remove the nozzle from the top of the sprinkler. On some sprinklers the nozzles can’t be removed, so you have to remove the whole sprinkler and install a short temporary pipe in it’s place. Turn on the water and allow the water to flush through the sprinkler for 4 or 5 minutes. Reassemble the sprinkler.
  • Sometimes the sprinkler riser gets so many scratches in it that the scratches catch on the wiper seal. In this case you must replace the entire sprinkler.

The water isn’t coming out of the sprinkler nozzles in an even pattern causing dry spots. How do I fix this?

The nozzle has something stuck in it or it is scratched. Replace the nozzle with a new one rather than trying to clean it. You can try to remove whatever is in the nozzle with a small screwdriver or a piece of wire, but this usually scratches the nozzle which will also cause the pattern to be bad, especially with plastic nozzles.

Nozzles are cheap, you’re better off just biting the bullet and replacing them. But you need to do more than replace the nozzle–Now you need to find out why there was something stuck in there.

Sometimes bugs crawl into the nozzles when the sprinklers are off.

See if you can figure out what is stuck in the old nozzle. Usually it is dirt or some other foreign item that was in the pipes. That means you need to flush out the pipes (which you really should do yearly anyway). Here’s how:

  • Remove one of the nozzles. Most sprinklers have a screen installed under the nozzle. Remove the screen. Clean it if it’s dirty.
  • Put on swimsuit or rain gear and waterproof shoes. Turn on sprinklers. Place your foot on the top of the problem sprinkler and gently but firmly press the riser straight down into the body. Do this several times to dislodge whatever is stuck in the wiper seal. This should correct the problem.
  • If the procedure above works, but a short time later the sprinkler once again starts sticking up it means you have dirt in the pipes. Remove the nozzle from the top of the sprinkler. On some sprinklers the nozzles can’t be removed, so you have to remove the whole sprinkler and install a short temporary pipe in its place. Turn on the water and allow the water to flush through the sprinkler for 4 or 5 minutes. Reassemble the sprinkler.
  • Sometimes the sprinkler riser gets so many scratches in it that the scratches catch on the wiper seal. In this case you must replace the entire sprinkler.

Replace the Irrigation Controller

Once in a while you may need/want to replace your irrigation controller clock. This is not a particularly difficult job, but it does require some basic knowledge of wiring and some planning.

First, make sure that your new controller is fully compatible with your irrigation system. Some things to check for: Does the new controller have the same number (or more) zones? Does the new controller utilize the same power source or is it battery operated? Can the new controller be mounted in the same place as the old controller?

Before disconnecting all the wires from your old controller it is a good idea to label the wires with masking tape or wire labels. This will reduce confusion when hooking up the new clock. To avoid a shock be sure to unplug the old controller before you begin removing any wires.

Read the instructions for your new controller before starting. It is often easiest to hook up the new controller as you remove wires from the old controller. This reduces the likelihood of confusing zone wires. Once the new controller has been fully wired, detach the old controller from the wall and mount the new one.

Test all zones in your system with the new controller to ensure it is working properly.

William Lowe
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