If wish to replace your existing radiator setup, you need to first note down the dimensions of the existing radiator. By dimensions, we specifically mean the width of the radiator. Choosing a bigger or smaller radiator in comparison to the existing one will raise concerns.
Imagine the pipes coming out of the wall or through the floor and the amount of extra pipework needed if a smaller radiator is chosen as a replacement. To make new connections, you need to get the pipework done above the floor level, which will give an undesirable look to the place. Incorporating the pipework underneath the floor will involve the hassle of taking up the carpets or floorboards or even cutting up the wooden hardwood or laminate floor covering. The entire process will become too time-consuming and expensive. However, if a change of flooring or carpet at the time of radiator replacement had always been a part of your plan, then that is altogether a different situation.
During replacement, apart from the size of the radiator, its positioning in the room is another factor to be considered from a heating perspective. For example, if you currently have an old leaking and corroded radiator bent or welded to fit inside the bay, then you might consider taking out this big single-panel radiator and replacing it with a double-panel radiator in the centre of the bay. The pipework can then be adjusted above the skirting or below the floor.