Well, that was pretty horrible. I pulled out the sponge and floaty thingy and the smallest net I have couldn't maneuver in that tight space. As I was contemplating what to do next, the heater exploded shooting glass everywhere. If I wasn't wearing a sweatsuit, I would have glass impaled in my legs and stomach.
So after much cursing, I pulled out the overflow tube and he didn't go down the hole, he just flopped around so I grabbed him with my hands.
This was a pretty awful evening and I sincerely hope that he is OK after all that.