I have an old gravity fed boiler, down Stairs in the property there are 3 radiators 1 in the hallway 2 in the lounge, all radiators have there own drops. The two in the lounge are very untidy so would like to cap both drops in the ceiling to get rid of pipe work on show. Then put two new radiators in the lounge but I want to pick up flow and return of the hall way rad is this okay to do so?