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!
I have a 18-20 year old Baxi, flow and return pipes are 22mm from the boiler to the front and rear of the house where manifolds reduce piing to 10mm to each rad. Each rad has the correct BTU @delta T50 for the size of the room. The piping and rads were installed by myself when we replaced the back boiler after moving in. With the boiler temp set at 58 it heats the house fine. Oversizing rads for a room running a system or combi boiler is not really a common thing to do and only really seen in the new fangdangled ground/air sourc heatpumps that are designed to run at ultra low temps.
@Jojoe If the system has no air in it, try turning the pump speed down a notch so water circulates slower and/or make sure your radiators are balanced correctly.
It would be helpful to know what system you have 🙂