I recently moved into a new house which has electric shower heads. One of the bathrooms had a cheap thin metal extension pipe attached to the plastic shower head outlet. My shower head does not use such an extension. The extension was really stuck in there, probably due to years of corrosion. I slowly added more rotational torque on the extension trying to remove it with an appropriate tool, but rather quickly the metal folded and tore, leaving the threading of the metal extension inside the plastic hole. I did try using pliers to remove the metal inside but it did not rotate which did not surprise me.
I got a "broken pipe extractor tool" (unclear of proper name in English, pictured below) to remove the old pipe fragment. When using the correct side and turning anti-clockwise as instructions plus youtube said/showed, it got tighter and tighter. Nothing happened though, the broken pipe did not come out. I decided to stop and remove the tool before risking any more damage to the plastic threads, especially since the tool was getting hard to rotate. The tool did start to be undone, but at some point it stopped coming out more. No matter which way I rotate the tool there is about low to medium friction and while the tool rotates it no longer goes in or out.
My guess is that the plastic threads are pretty much destroyed at this point. The probably mangled metal that existed inside the hole could also be digging into the plastic. I'll have to refurbish the plastic threads, but first I need to get the tool out. Being a rental I can't remove the tiles to replace the plastic piece.
Rotating the tool in either direction does not help. There is a hole in the center which I can use for some sort of pulling force, but that did not help. Trying to pull while rotate (which can be useful for threaded screws) is very difficult. If all of the piping was metal I could use heat, but heat can't be applied to the tool without melting the plastic (though maybe this is the only solution at this point? I will have to refurbish the plastic somehow anyway).
I did try drilling out the tool with my current metal bits, but being hardened steel I did not expect this to be much of a success and it wasn't. I could probably do it with some really good steel drill bits, but it's a very long way to drill and the drill will have to be dead accurate for the entire distance so I don't really like this approach. Even if I do drill the center out I still have to get the steel bits out.
I have considered using some "percussive maintenance" with a hammer as apparently that can be useful with this tool, but at this point I have not attempted this yet.
Having just moved, money is a bit too tight for a plumber right now but in January that can become feasible if I can't find a way to get the tool out.
