Low pressure at zone 4

[NedNimrod]

Hi to All,
My system has 4 zones. Three put out a goodly amount of water. The pressure is abt 40 lbs. The 4th zone starts out ok with enough water and pressure but the pressure starts to drop immediately from 40 and in about 1 minute it's down to 17 lbs with with a big decrease in water. It remains at 17 for the whole time.
What is causing this? I don't see any real wet spots in the lawn.
Thanks,
Ned

 

[Jimbo]

A leak or broken head would be the first suspect. Otherwise, check manual operation of the vavle, and make sure it is not throttled down.

 

[Sponsor]

 

[Verdeboy]

Could be an underground leak that hasn't made itself obvious yet. You may also have a partial blockage in the line or in the valve. Or, just too many heads on that zone.

 

[NedNimrod]

I have less heads on this zone than the others.

 

[Verdeboy]

I have less heads on this zone than the others.

Did you recently do any work on that zone in which you could have clogged the line with dirt or stones? It's really easy to do that even if you're just replacing a broken head.

 

[NedNimrod]

No, I haven't done anything for a long time. Is there anyway to test the line?

 

[Verdeboy]

Just start removing heads until you find where the pressure drops.

 

[Wet_Boots]

Try operating the valve(s) manually, without using the controller.