I have just replaced the diaphram on the diverter, I followed the link on here showing the breakdown of the diverter. worcester do not list the diaphram as a spare, they suggest changing the whole diverter,as this was on my own boiler i thought i would try it first, as someone posted its a tw--t to change but the diaphram kit was bought for £11.56 bit of difference from £75/80 fir the whole thing. just a thankyou for any help and the posts that helped me on here