Hi all, Im a new home owner and pretty clueless when it comes to DIY; however being a homeowner I feel DIY will becomes my best friend! And so this morning i faced a challenge unlike one i have before.... I leave the sanctuary of my bedroom at the front of the house to hear a noise, in hindsight sounds like it is a pump that is struggling to get water into it (this being from the mobile pumps we use use on our caravan) either that or it sounds like it needs a good oiling! I go into the airing cupboard whre the noise seems more prelivant and all seems well, but the noise is in the entire house, other then the front bedroom. As soon as i tuen the central heating off the noise stops. I have bleed all the radiators, includiong a valve in the airing cupboard that had a little air in. To be fair all the radiators had loads of air in, with the least bit in the front bedroom. I turn heating back on and noise returns, not as bad as before but still significant to worry me. I bleed radiators again but all ok. Now im stumped. I am going away this weekend at 11am so dont want to be worrying about the heating system. Excuse my naivety but we have a airing cupboard which goes into the attic. In the attic, next to the barel is what looks like a toilet cistern with rusty water in....im guessing this is the radiator water?? I have read about turning pumps down for sludge build up, but i wouldnt even know where to find the pump and what is this stop cock thing going to turn off in airing cupboard. Can anybody help please?? Regards Clueless?? EDIT: The heating has been off about 20 minutes since starting the 2 bleeding processes. I have turned the heating back on and no noise at all now....is this likely to be working or simply a result of dropped heat/pressure? If i stay noise free for another hour can i consider myself fixed?