I had irrigation system installed last fall. It was winterized by the contractor who installed it. This week when I started it, I noticed one of the head was not popping up. All other heads in this zone are working fine. I think this is the last head from that zone. I do see water coming through that head though. While the system was on I also tried to pull it but did not have any luck.

Any idea what could have been wrong here ? Is it possible when someone drove on top of this head it broke spring or something else required for pop up? I am planning to pull the head out by digging around. Am I on the right track?

Thanks.