On Wed, 02 Feb 2011 14:35:02 +0000, Piers Finlayson wrote:

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).

Our propane-burning forced-air furnace sometimes does it, too, but not
always. As it's not consistent I've always assumed it's something to do
with atmospheric conditions (temperature, moisture content in the
combustion air etc.) rather than any kind of fault, but maybe it really
is a maintenance issue... (the furnace control board never displays any
kind of fault condition)

cheers

Jules