I have a leak in my biasi 24s diverter valve, more specifically it is coming from the actuator at the bottom where both parts of the actuator meet. Its a slow leak which reduces the water pressure but does not effect the hot water and central heating operation. I have taken the actuator out and taken it apart, there seems to have been water inside. The diaphragm was fine apart from a bit of warping (so it was not flat against the casing) no leaks. The casing had pitted with green substance so cleaned and scraped it away. Placed back on the boiler and it still leaks (possibly not as much though). Any advise as to whether I would only need a diaphragm or full Diverter repair kit? I have attached photos.