There’s a risk of introducing a red herring here Oscarmax. Unless the heating system is newish and designed around a low temperature boiler, the radiator sizing would have been designed for a boiler flow temperature of 82 Deg. What Jojoe is experiencing with a low boiler flow temperature is expected and normal. As the weather deteriorates he will need to keep edging the boiler temperature up to keep his room warm. Unless it’s a newly installed system, to run a boiler at low temperatures needs bigger radiators (and pipes). And possibly even a bigger boiler!
Where is the red herring?
Unfortunately I have suffered a brain injury and occasionally I get confused and often say the wrong thing.