Well I bought a vamo and a protank, was fine for a week or so then when I unscrewed my protank to refill the protank wouldn't screw back in , it seems as though a ring for want of a better word has come off the screw of the protank and wedged into the centre hole at top of the vamo and cant get it out. Im not sure whats faulty the protank or the vamo but it just wont screw back in its just loose!!! :-(