I spent time camping the East room from the maze, as well as camping him in the West room and no joy.
I finally spent time camping him at the bottom of the slope just where you have to click the torch to open the wall. There are two ice golem's that spawn in alcoves either side of the path. I camped there and got him to spawn after about an hour.
Due to this and the rest of the posts below about how he spawned in different spots for others, I can only suggest any ice golem is his PH.