Banging noise when unit starts in attic
(Lawrenceville, GA. USA)
Just as the attic unit fan begins to blow there is a banging noise as if it's having a hard time starting.
I have had service people out 3 times and they can't find what is wrong. Of course it doesn't do it while they are here.
Now I have noticed the lights dimming, just a little, as the banging is getting worse, and louder.
Will call service again, but maybe someone can give me an idea of what is going on.