It is easy to find out if your heating system is performing well.
Is the top of the radiator hot as well as lower down?
If it is cold at the top, it needs bleeding. Air in the radiator makes your radiator less efficient, effectively reducing its surface area and making it perform like a smaller one.
You will need to do this with all your radiators, of course.
Check the pressure reading on your boiler.
The pressure gauge should read above one bar, unless it is a low pressure system with a tank in the loft.
If the pressure is too low, the pump will not work properly and you will waste gas.
Before 2005, radiators were small and very hot.
Radiator covers, often used to protect against burns, make the radiators much less effective.
Larger radiators give you more wiggle room, as they are more likely to be able provide sufficient heat at lower water temperatures.
Is there furniture in front of your radiators?
This matters more with small radiators.
Even a shelf above the radiator reduces its power by 5%.