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