Stuck shower thermostatic valve

[pipefox]

Help! The shower thermostatic valve has snapped with half of it stuck inside (the front and centre of the valve are out). Long nosed pliers and WD40 have had no success, and the whole fitting is moving when trying to pull. I was thinking it might be possible to get something in, attach to the stuck part, and then screw it out using the casing as the counter balance.

On the image the outer brass ring is the casing the valve screws into, the inner brass ring is the valve where it has snapped and the hexagonal shape at the back end of the valve. Any ideas what I could use to attach to the back of the hexagonal hole to get a grip then I could put a bar across the outer casing and screw it out potentially.

Other ideas also welcome!

Only suggestion so far is to tear out the tiles and replace entire fitting but entire bathroom tiled so REALLY don't want to do this.

 

[steadyon]

Try getting an appropriate size Allen hex bit and use with a 1/2" or 3/8" square drive socket extension to try and unscrew via the hex at the bottom? If it won't turn, then there is no way its going to come out by pulling. If it does turn, a bit of WD40 or similar, and a bit more turning might loosen it enough to pull out with pliers. As the thermostatic capsule is out (at least, I can't see it) you could try pouring boiling water on the valve. The thermal shock of expansion might be enough to loosen it a little.

I know measuring the hex isn't easy but you could try various round bars until you find one that just fits, then the diameter gives you the "across the flats" measurement. Alternatively the head of a long bolt, or, as a last resort, plasticine on a long rod. If you have, or can borrow, a set of set of Allen hex bits, no need for the foregoing.

Are you sure the valve is broken. These normally come apart, with the two parts screwed together and sealed with something like high strength thread locking compound. The hex is normally used to screw the two parts together during manufacture. If the thread lock fails, the cartridge will come apart as yours has.