On Feb 2, 8:07*am, Piers Finlayson wrote:
My oil fired boiler has started whistling while running. *The
high-pitched whistle starts about 10s after fireing up, stays pretty
constant while running and then tapers off after the boiler
extinguishes itself.

Any suggestions as to what might be wrong? *I've seen various
suggestions around a build up of limescale, but they seem to normally
be referring to a much lower pitched rumbling sound.

Thanks,
Piers

Make and age would help.. Fan motor bearing sounds a possibility.

Al