On 2011-02-02 12:57:53 +0000, Dave Liquorice said:

On Wed, 2 Feb 2011 08:07:16 +0000, Piers Finlayson wrote:

My oil fired boiler has started whistling while running. The
high-pitched whistle starts about 10s after fireing up,

A Mistral Diamond. No idea of age, but instructions dated 2000.


Define "fireing up" do you mean blower starting or when the ignitor
fires to light the boiler some seconds later?

The latter (i.e. after the whumpf - a techincal term).


Thinking that it might a worn jet if it hasn't been serviced/replaced
every year or so. Though I'd expect that to stop PDQ after the blower
stops.

The jets haven't been serviced or replaced for a few years. Whistling
stops fairly quickly but not instantly - fades away over the course of
a few seconds. Of course it's not doing it now.


Kettling due to scale can be quite high frequency but I wouldn't call
that sound a "whistle", ie a single tone, it's more high freqency
noise.