Thumping Sound When Indoor Fan Spins Down
Recently my indoor blower has gotten extremely loud. There is lots of vibration on the handler unit when running and when it cuts off, as the fan spins down there is very distinct and timed thump as if the fan is out of balance or it is hitting something.
With each revolution of the fan there is thump. I can sit there and count the thumps until the fan stops rotating (usually about 6-8 revolutions).
Eventually I figure it will give out. It is 11 years old and I already replaced the outside unit about two years ago.