I finally figured out the best way to un-stick a sprinkler head that won't go down. Just put a little Vaseline on the spray head shaft. It won't wash away... been thru 3 cycles already with zero stuck spray heads.
Depends on the problem. Vaseline is fine if you just need lubrication. But if you are having problems with dirt sand or debris jamming it, vaseline can make the problem worse.
First thing I do is push the head up and down a couple of times while it is operating.
If that doesn't fix it, I use a silicon spray for lubrication.
If the problem re-occurs, replace the sticking head.
Thanks for the suggestion. I usually check for debris by removing the heads first. I made a special hose to wet vac out the body so that I can avoid having to make a mess by flushing it. My particular system is a commercial toro xf-416. When I bought my house the system was completely dead. I had to repair 3 major leaks in the lines and replaced about 20 heads along with the xf-416 controller. The ones that usually stick are the smaller 570 heads. After using Vaseline I have had no trouble... I used everything from silicone to wd 40 and those tend to wash away after 2 cycles. I've run 6 cycles now and it's still working like a champ.