I an a non-pro DIYer. I am tyring to replace the old hot water cylinder. I used the old connectors from the old cylinder and a new copper blue cylinder. However, after I cleaned old connectors and used the tapes, glues etc. to stop the water leak, the water is still slowly leaking. I wonder if I missed some rubber washers for the top and bottom connectors. The coil connectors seemed a bit better. Any advice is welcomed.