Can you confirm that the cold to the shower is a separate pipe all the way to the cylinder?
Also, you say there is no flange to the cylinder. You do, however, have a separate pipe all the way from the shower to the cylinder for the hot? And how does this connect to the cylinder? Can you photo or sketch it for us?
Also, you say there is no flange to the cylinder. You do, however, have a separate pipe all the way from the shower to the cylinder for the hot? And how does this connect to the cylinder? Can you photo or sketch it for us?