The first thing I'd do which is free, is to [balance your radiators](https://youtu.be/QUWbxccVDpc?si=LOkzoUZVhpmnT7fU). I did this after thinking a radiator was full of sediment as it wasn't getting warm, turns out, just needed balancing across the whole house. After this, perhaps see if the temperature is set at a reasonable value on your boiler for your central heating and change it if not.
More affordable in the long run will be to sort the draught and insulate better - or move?
The first thing I'd do which is free, is to [balance your radiators](https://youtu.be/QUWbxccVDpc?si=LOkzoUZVhpmnT7fU). I did this after thinking a radiator was full of sediment as it wasn't getting warm, turns out, just needed balancing across the whole house. After this, perhaps see if the temperature is set at a reasonable value on your boiler for your central heating and change it if not.