The answer to this question depends on how new/old the sprinkler heads are.If your sprinkler heads are relatively new, chances are you just need to clean them out. Dirt and debris can get lodged in the small space between the pop-up nozzle and the body of the sprinkler, causing it to say up. If your sprinkler heads are relatively old and cleaning them doesn’t work, it’s probably time to replace them. For more detailed information on how to clean or replace sprinkler heads, check out this blog post.