Cold rooms, noisy pipes and radiators that never get warm at the bottom are usually a system problem, not a boiler problem. I put heating systems right rather than papering over them.
I balance the system so the far bedroom gets the same treatment as the hall, size radiators to the room rather than the space on the wall, and sort out pipework that was never right in the first place.
If the water coming out is black, the system is full of sludge and a power flush plus a magnetic filter will usually transform how it performs.
A smart thermostat, thermostatic valves on every radiator and proper zoning give you real control over the bill. I fit Nest, Hive and Tado and set them up before I leave so you are not fighting an app.

Northumberland
A single radiator that was never big enough for the room, swapped for a larger vertical designer radiator that actually heats the space.

Northumberland
A whole heating system put in from scratch: new boiler, new copper pipework run under the floors and radiators sized room by room.

Northumberland and Newcastle
Cast iron, column and designer radiators fitted in period homes, with brass and antique valves and neat copper tails through the floorboards.
Tell me what you need and I will come and look at it. You get the price before I start.