Noisy Bolier

[chairman]

Please help!!
I inherited a Baxi burmuda back boiler which was new at the time 5 years ago when i moved house. the system is a fully pumped open vent system.
This boiler when installed was fitted to a one pipe system which i had updated to flow and return with new rads. Part of the pipe work is old steele threaded pipes leading from the boiler to the cylinder.
My problem is noise like kettling/banging and whistling.
An engineer comes every now and again and adds a pink liquid which he states is a desludger and limescale remover which seems to do the trick but for a limited time.
He has diagnosed the problem as limescale in the boiler with sludge which is treatable but will take time. I don't want to bother him every five mins and am capable of adding stuff to the system, but what? It has to be non acid based because of the old pipes.
Any ideas gratefully received

 

[sterose]

you mention kettling - i have a rushing sound every time i turn CH on - or rather had, because i had a new boiler installed on friday.

The haeting engineeer told me it was 'kettling' - but what is it?

And to be honest, i almost miss the sound of the old boiler firing up - you get used to hearing certain sounds, and its strange when you dont hear them.