On 2004-10-18, Winged Cat wrote:

Fairly sure that Elans are natural draught with open or balanced flue
variants.
Might be some sort of flame/burner problem. Start with a good clear out
and thorough check over.

Thanks for the advice so far.

It is natural draught so the noise is not flu related. The noise is
definitely associated with the water being heated, as it starts off
quitely when the boiler commences its cycle, the gradually increases
in volume as the water gets heated, reaches a plateau, and then ceases
when the boiler cycles off again.

My ~15 year old Ideal (Stelrad) New Mexico Slimline has benefitted
greatly from a shot of the (screwfix supplied) Purimachos boiler
descaler and the inhibitor in to too after a full drain down.

It used to make a noise like that which you describe - but now - 3
weeks later it's almost inaudiable in the kitchen - and the whole
system seems to be a lot quieter.

Big thanks to AndyH/Ed for the advice in the first place

Cheers
Dan