Edit: This is not a bug.
I have 2 steam geysers in my colony. Both of them still animate when emitting water but one of them appears to have stopped spawning in more water. I couldn't find anyone else with this problem so I'm not sure what is actually happening here. Here is a screen shot of the animation but no actual water dripping down. http://imgur.com/a/nQ86L I can try and find a save file before and after the geyser breaks if this turns out to be a bug.
Wait for slime to emit well over 5k pressure on top of your geyser.