hi i have took a oil boiler out with the radiator central heating pipes going though a wall then under a tiled floor . The main hot water tank pipes , flow and return come out of the side of the wall where a rayburn used to be . After putting a rayburn back in place can i connect the radiator central heating pipes into the rayburn back boiler to hot water tank flow and return pipes without to many problems as this would be more or less the same idear as when a back boiler has flow and return fittings on both side of the back boier ie 2 flow and 2 returns