SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

Thank you again for staying with me.
Is there a way to remove the spring (of Hunter's PGP and/or I-20 series risers) so that I adjust or replace it ?
I am kind of temporarily disabled now and my next activities with the sprinklers won't happen for a few days.
(Worked too hard on an electric massage machine in prep for playing golf and must have overworked on it. Severe back pain developed a few hours afterward and can hardly walk straight, let alone bending my body to work on the things close to the ground.)

I believe the springs are stronger. That could be the problem.
There's always the possibility that the valve isn't coming on all the way or there's a leak in the pipe somewhere.

To: mrfixit

Thank you.
I think I am getting some handle about how to write my follow-up messages.
I found a "Write Reply" button at low right side, where I am appending my messages now.

By the way, the whole issue might have been related my choice of nozzles, I mean, I might have used larger nozzles that allow higher water usage, thus reducing water pressure of the zone in operation.
This morning, I only swapped those risers within easy access. I will check on the others later on and change some of the nozzles to smaller ones per your suggestion.

Thank you very much Mr.FixIt.

June 23, 2017 9:10am E.D.T.
So, not knowing where/how to write my follow-up report, here is what I found out:
Replaced at 8:30am a known good riser with a known bad riser(that does not rise without my pulling it up).
Now, they both work fine without my help. It so happened that those I swapped were both of I-20 SS model that were at locations easy for me to swap. My sprinkler systems is usually set to start at 4:30am but when I was checking on the operation of these risers were often during the day when water pressure might have been low. The village engineer confirmed that a typical water pressure for this area is 66 PSI with minimum of 30 PSI as set forth by the village code but it never goes that low. I am wondering where I can find the water pressure in Hunter's I-20 sprinkler head specs. If you know, please let me know.
Meanwhile, I correct what I referred to as "I-20 Pro". I should have said "I-20 Ultra".

June 22, 2017 14:00 EDT
Thank you for the suggestion, to try changing the head with known good ones.
I will do and come back in a day or so with my report.
In the meantime, this sprinkler system is 20 year old and has been working fine until I recently replaced some of the heads with new ones. The systems originally had Toro heads, which I replaced with Hunter PGP heads one by one during the past 20 years whenever I noticed problems with a certain head. Those heads I have problems of Rising are at the same location where older PGP and I-20 used to work fine. I wonder whether I-20 (I-20 SS) heads are equipped with springs stronger than those used in PGP, requiring more water pressure to allow the head to rise?

Please let me know where I can write in response to yours. Without the knowledge, I wrote as an edit to my original.

Have you tried swapping the sprinkler that doesn't work with one that does to see if the problem moves with the sprinkler or stays in the same spot?
Could be too many heads on the line. Maybe downsize the nozzles.

My new I-20 and also I-20 SS have problems rising unless I grab the rising part and pull up, which is totally impractical. The problem is not for all of the Hunter I-20 and I-20 SS I replaced last week. 7 others (combined number of I-20 and I-20 SS) that I replaced at the same time are working fine. I read in a forum that someone was recommending to remove and clean the top assembly to get sands/soil out of it with water. Mine are new but cleaned them anyway just to make sure nothing foreign got stuck when I first installed them last week. Naturally, I suspected water pressure but the area where they are installed, namely Scarsdale, NY, is known for high water pressure among cities/towns and villages in Westchester County (NY). I am considering to change them to yet another Hunter sprinkler head model I-20 Pro. I know there is no guarantee but am just hoping it may solve my problem. Learningat80, Fingers Crossed!

June 22, 2017 14:00 EDT
Thank you for the suggestion, to try changing the head with known good ones.
I will do and come back in a day or so with my report.
In the meantime, this sprinkler system is 20 year old and has been working fine until I recently replaced some of the heads with new ones. The systems originally had Toro heads, which I replaced with Hunter PGP heads one by one during the past 20 years whenever I noticed problems with a certain head. Those heads I have problems of Rising are at the same location where older PGP and I-20 used to work fine. I wonder whether I-20 (I-20 SS) heads are equipped with springs stronger than those used in PGP, requiring more water pressure to allow the head to rise?

Please let me know where I can write in response to yours. Without the knowledge, I wrote as an edit to my original.

June 23, 2017 9:10am E.D.T.
So, not knowing where/how to write my follow-up report, here is what I found out:
Replaced at 8:30am a known good riser with a known bad riser(that does not rise without my pulling it up).
Now, they both work fine without my help. It so happened that those I swapped were both of I-20 SS model that were at locations easy for me to swap. My sprinkler systems is usually set to start at 4:30am but when I was checking on the operation of these risers were often during the day when water pressure might have been low. The village engineer confirmed that a typical water pressure for this area is 66 PSI with minimum of 30 PSI as set forth by the village code but it never goes that low. I am wondering where I can find the water pressure in Hunter's I-20 sprinkler head specs. If you know, please let me know.
Meanwhile, I correct what I referred to as "I-20 Pro". I should have said "I-20 Ultra".