Noises in the central heating are Some of most common problem with the heating and radiators system, usually while the system starting or running , it can be water hammer, whistling and chattering, some of this noises may not be caused from your central heating system
In designing the plumbing system your experinced plumber will try to make it as noiseless as possible.
The noise is normally due to water travelling at a high speed in your central heating pipes , Your Gas Safe Registered Engineer when designing your heating system will use Larger pipe to provide a more adequate supply of water and will reduce noise.
Also you can find some general types of noises in some of the older plumbing
