A radiator that wrecks a wall is usually the one you painted around
I painted the sitting room in May and left the radiator where it was. I cut in around the edges with a brush and rolled what I could reach. In October I turned the heating on and saw the wall. A dirty rectangle, last year's colour, a strip of fluff and dust the roller had never touched. The new emulsion stopped in a halo. I had not painted a wall. I had painted around an obstacle and then advertised it all winter.
A radiator sits on brackets. Many will lift up and come forward a little with the pipes still on. That gap is enough for a slim roller or a pad. I do this when the heating is off and the metal is cold. I am not draining anything. I am not rebuilding a valve. The rad is in the way. I move the way, or I use a tool that fits behind it.
If the rad will not come forward, I do not invent a plumbing job. I use a long, thin roller, a radiator brush, and patience. I still take the time to do the wall behind, not only the bits I can see from the sofa. People blame the colour match in spring. The tin was the same. The miss was the shadow I left.
A dust sheet that leaks is usually the gap at the skirting is the floor under this. I tape the sheet to the skirting and I put a bit of sheet under the rad as well. Paint behind a rad finds the floor through the brackets. I have dripped on a pipe and watched it run to the board. A roller that sheds is usually the cheap sleeve is a bad sleeve in a tight gap. Fluff behind a rad stays there until the next time you lift it. I tape a new sleeve before it goes in that slot. Masking that bleeds is usually the wrong tape is the valve tails and the pipe if I want them clean. I tape the metal, not the wall I am trying to paint.
UK year is the off season. Late spring and summer, heating off, windows you can open. I will not lift a hot rad in January to save a weekend. I will live with the old wall until May, or I will do the rest of the room and come back to the rad when it is cold. A warm rad skins emulsion as you roll and then you have a tacky patch you cannot see until it yellows.
Skip painting the visible edges and calling the wall done. Skip standing on the rad to reach the top. Skip a full-size roller forced into the gap until it prints a ridge of paint on the back of the panels. Skip taking a valve apart because the rad would not lift. If it will not lift, it stays, and I paint around it properly with a slim tool. Skip leaving wet paint on the brackets so the rad sticks when I hang it back. I wipe the hooks.
I also look at the wall before I roll. Dust and cobwebs behind a rad become part of the film. I vacuum the slot. I do not sugar-soap a space I cannot rinse. A dry brush is enough in that gap.
When I hang the rad back I look from the side, not only from the sofa. If I can still see last year's colour, I have not finished. One more pass with the slim roller beats a winter of a framed patch.
I do not need a new colour because the last wall showed a rectangle. I need the heating off, the rad forward or a slim roller in the slot, and the wall done as one face.
If I later add a buy link here, it will be a paid promo.