Hello. This boiler is a Potterton Neataheat, one of those 1522/1622. I bought a Shower Pump and it was supplied with a Surrey Flange 1" X 22mm Top Entry Flange. I contacted a plumber, he came, and after looking at the cylinder he said the flange was too big. He said I should get a Warwick Flange. He did not give me a part number or what size to ask for. As a result of something he said, I am not sure if he could actually do a good job. However, if that flange is too big then I need to get a smaller one. Any advice on this please ?. Thank you.