Radiator suddenly stopped working. I read a few posts and they got me as far as thinking it might be the TRV head that needed removing and then the pin head that may need tapping. I couldn't get the head off however, but managed to remove the two black locking pins. After I removed the two black plastic locking pins on the Myson TRV the radiator is working, but what do I do with these locking pins? Can I now put them back in? I don't know why removing them made the rad work again either. Any advice, knowledge on the issue would be much appreciated. Cheers.