So as the title sez i want to add a radiator to my existing system i plan coming of an existing flow and return pipe, my heating is plumbed in 15mm copper pipe, i hope to come off an upstairs radiator (bedroom) and bring pipe work to downstairs drill through a wall and then fit the new radiator (conservatory) does this sound ok?? am i right, i would have to balance the two radiators turning down the first radiator until heat starts running down to the new radiator, any help and advice would be grate thanks