Rayburn noises

I have a five year old oil fired Rayburn which has started to make some strange noises. It has a fully pumped system for both hot water and heating using two motorised valves. The boiler used to trip quite regularly due to the pump over run loop being to short but this has been rectified, it also used to make gurgling swishing noises but one of those can shaped devices was fitted (sorry, don't know technical name) and that stopped. It has worked well for four years now. For the last few days, when the boiler has completed a burn cycle, the boiler as made a noise similar to when you first switch on a kettle (a sort of screeching water/air noise) which last about 30 seconds and then stops. The motorised valves are working, the rads heat up quickly and I have bled them, the pump works well and does not seem to affect the noise in any way when I change its speed or momentarily turn it off. The noise is now happening when the boiler fires up but the volume drops off after 20 seconds. Could the noise be caused by a pinprick hole in the boiler itself?

sounds like you need some ceraboard.

Try some boiler descaler, like Kamco System Hush. Fernox and Sentinel do similar products.

so the original install Later required an air separator then the over run loop modifying .........maybe it was like the one I looked @ yesterday .....total lash up pipework .....I`m not a Aga /Rayburn expert but I can follow their installation instructions........there`s at least one done all wrong..........un be ****ing lievable