Hi Jen has this just started or an old problemb? but sounds like a build up in the pipes of scale, is the system an open or sealed? if open then you can get some scale/noise reducer from your local plumbing suppier, and pour it in the header tank, PLEASE make sure it is the small header tank and not the large one if only one tank then you may need to call out someone to do this
Hope this helps :lol:
hiya jen sounds like there is air in your heating sytem try bleading the radiators to see if this helps If you have a sealed system dont forget to top up the system after bleeding via the filling loop.