I’ve done a bit of basic plumbing over the years, but never replaced a CH rad. Fortunately, it’s a small one (500mm wide & 700mm high) in the bathroom. This house was built in the 60’s and everything about the CH was squeezed in the 1980’s. The seam on the end of the rad has become quite rusty and there’s rust on the underside seam too, but no signs of leaks yet (but it’s over 40 years old). The pipe to pipe centres are at 540mm feeding in at the bottom.

I’ve looked at quite a few radiator suppliers on the net; my impression is they don’t want to sell really basic single panel stuff like this but “posh expensive stuff” instead, and I had to look around for a while to find what I want which I think is this;
https://www.theradiatorwarehouse.co...MIh8vY8PfAlQMVm0JBAh1o_AazEAQYByABEgIjefD_BwE. at £69 inc delivery &VAT (I can live with 750mm). Does the team think this is a fair choice?

Have you tried Screwfix? Used to be cheap

Pipe centres will be quite adjustable, if you have 3/4 valves then replace like for like

Basic single panel will put out less heat than the convector type of the same size though the convector stands further from the wall.
If you feel tempted cheap chrome towel rails have less plating than dearer ones.
Don't forget the inhibitor, though if you can isolate all the rads you can collect the water in 2 or three buckets as it's only upstairs unless it's too black with suspended rust.

Basic single panel will put out less heat than the convector type of the same size though the convector stands further from the wall.
If you feel tempted cheap chrome towel rails have less plating than dearer ones.
Don't forget the inhibitor, though if you can isolate all the rads you can collect the water in 2 or three buckets as it's only upstairs unless it's too black with suspended rust.

The bathroom is sandwiched between two bedrooms, the airing cupboard is on one side and it's on the south-facing side of the house. Mostly, the rad stat is set at only little above "nominal".

I actually started this morning to check all the rubber O rings on my beloved Pegler Belmont radiator valves. It's possible I have not checked those for a while but they all seem fine, and I am replacing the rings anyway and then a good flush before new Fernox!

screwfix does 700 wide

double

single

search reference

Wickes do a type 11 (single panel) 500 mm width x 700mm high for £54.

If 500mm width x 600 mm high would be powerful enough then Toolstation do this as a type 11 for £29.

I’ll second the Wickes radiators having bought some last year. They’re made by Stelrad and are identical less the little plastic trims you don’t get on the Wickes ones but not surprisingly the plastic trim fits.

They have the majority of the smaller sizes in the warehouses too with no need for delivery risking it being bashed in transit.