I understand my toilet cistern has a "Beta valve" flush mechanism. The washer cutting off the flush when the cistern empties has perished and I need a replacement. I've tried local plumbers merchants and get the "Thats a Beta valve part" and "we don't have a spare"... It's about 6cm dia with a 3.2cm hole and 6mm(ish) thick at the centre tapering to the outside
Can anyone help me finding a replacement rubber washer for this flush mechanism?