flashgorman wrote:
"Richard Sterry" wrote in message
...
flashgorman wrote:
Hi,

I have a hood type extractor fan over my hob. Lately this has given up
on its extracting duties. When I turn it on theres the usual whizzing
noises but no air is being sucked up into the hood. I took the cover
off the hood and removed the filter (pretty clean). There's a big fan
that spins round at an impressive rate but I can't feel any updraught
of air into it. I climbed on to the kitchen roof and checked that the
vents are clear and you can feel a slight draught coming from the vent.

Any clues?

Is there a build-up of fat/grease somewhere in the ducting?

Not as far as I can insert an arm, James Herriot, style, at either end.

....then it would appear to be defying the laws of physics! If the ducts are
clear, the outlet grill is clear, the recirculate/extract lever is in the
right position, and the fan is going round at a decent speed, then it MUST
draw air through. If air is not being drawn through, then one of the
previous assumptions/observations must be wrong.

Unless it's the unknown factor 'X' of course. ;-)

Rick