OTOH, fitting a radiator, even with a bit of pipe extendificationising, is the sort of plumbing even I can do ...
Kim's done much more complex stuff than I have, and I managed it once, as well. My brother came to stay, so we moved my (then young) daughter out of her room overnight. He's a building services engineer, so he took one look and said that the reason that her room was always a bit cold was that the radiator was under-sized. It's the box room, and I think Wimpey had realised that an appropriately-sized radiator would prevent a bed from fitting in as well...
My brother recommended a two-panel radiator because of not taking up wall space, and I found one of the same height and width as the original. We managed to get one of those high bunks with a desk underneath, again because of it being the box room. The two are an interference fit. I had to build the bed completely in situ, doing all the back screws first.
That was several decades ago, and I've no plans to move anything, not least because any replacement probably wouldn't fit.