This job didn't involve fitting the radiator from scratch but refitting it as the old fixings weren't upto the job for such a heavy load.
The radiator was removed, then the holes patched and painted. I had to slightly move the radiator further up to use solid undamaged wall, drilled about 6 inches into the brickwork, and used double depth nylon fixings. One of the holes was still mushy so I used a chemical anchor to fix it into place.
Rehung the radiator and it was clear the top 2 fixings alone were able to take the weight to I was happy with all 4 in place.
If you need something hanging with the ultimate degree of accuracy, I use a laser level to ensure it. Useful for tiling, hangings, and many more odd jobs.
Just finishing up some exterior paintwork this week. Grinded off loose paint from the sills and lintels, Epoxy mortared some cracks and painted with professional undercoat and exterior flexible gloss. This is about as late as I'll do outdoor paintwork before winter. I now book stuff for April.