My front yard has 8 spinkler heads and 3 of them have very little water pressure..?

Question

The 3 that don't work as well are hooked up to the same system. They worked until I had to replace a couple. I have compared the replacement parts with the old parts and they are exactly the same. Water pressure through those 3 are so weak, that my lawn is starting to die, in those areas. Not quite sure what I should do!!??

Answer 1

well abviously something is not the same if the pressure is low.
try cleanning the 3 spinklers or putting the same ones as you just did on the first 5.

Answer 2

I'm assuming all 8 are spray head type and not rotors (the kind that shoot a single stream and rotate). How did you replace them? The entire unit or just the nozzle? Even though they may be the same body, are the nozzles the same as what you had? Did you include the nozzle screens? If you replaced the entire heads, did you flush-out the system before re-installing the new sprinklers (run the water to ensure it runs clean before installing sprinkler/nozzle)?
You may have gotten debris in the lines which will clog up the nozzles - particularly on the lowest heads. Try taking the nozzles off and check the screens/nozzles for debris. If everything is correct and nothing else has changed to the system, what's going on in the neighborhood? Is there new construction near by?
A sprinkler zone (your 8 sprinklers) only has so much water and pressure supplied to it. It's common in newer neighborhoods for the pressure to be higher for the first few homes (the pressure supplied is what's planned for when the subdivision is complete). When this happens, most homes have pressure regulators to keep the water inside the home at a constant pressure (usually 35 - 50 psi). Sometimes, and at my house, the sprinkler system bypasses the pressure regulator, giving a lot more pressure that may drop over time as new homes are built (mine has dropped 40 psi since new homes have been added).
But, based on the information you've provided, it sounds as if the system is stretched...meaning too many heads on a zone (you either don't have enough gallonage or pressure to run the system). During times of stress, you'll see this by having dry spots where around the heads the grass is green. (But, since it worked fine before, it makes me think the nozzles are not the same - perhpas you had low-gallonage nozzles on there before?).
What does the stream look like coming from the heads? Is the area covered flat? Could a connection be loose, allowing water (which you can't see) out of the system and reducing flow/pressure?
If I had more information, I could diagnose and tell you how to fix it, but this is the best I can do with the information provided.
Good luck.

Answer 3

Call a repairman to fix them if you can't resolve the problem, but in Austin it costs very little even for a whole yard test.

Mine had a rock in the controller underneath the ground, some were watering the house instead of the lawn, fire ants were causing problems with the heads, clogged heads, some heads were sunk too far in the ground....use a hose and manual sprinkler until you get this resolved.

Answer 4

Something may be clogging them. Have you removed the heads and turned on the system? You may find the culprits.

Answer 5

holes may be plugged or clogged......try to push a pun through each one of them to make sure they are open