* Dust collects on the fins, of the fanblade. Some of the
dust may have shaken loose. Dust interfered with air flow,
and makes the blades off balance.
* Fan blade can rub on other parts of the unit.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


wrote in message
...
Hi,

We have a Friederich 18200 BTU through the wall air
conditioner on the
main floor of our house. It cools the entire first floor
and has been
a great AC for us for over 12 years. It runs on a 240 volt
line which
was properly installed when we had our kitchen remodeled.

Recently it started making this loud vibrating noise like
the fan
couldn't get started or was somehow out of balance. I would
compare
it to the sound of a washing machine when the load is
unbalanced.
Sometimes it wouldn't even run the fan at level 1 so I would
put it up
to level four (the fan has 4 speeds) and then the fan would
kick in
but it would be really loud and vibrate a lot. The cooling
part works
fine, it is just the fan that is having problems.

Then it just started working again and today it is working
fine
again. It was broken like this for the last 5 days. All of
those
days were quite hot.

I remember this happening once last summer and it fixed
itself and we
made it through.

I would appreciate if anyone has any idea what might cause
this kind
of vibration in the fan and why it could just get better on
its own
without any service.

Thanks in advance,
Steve