The blower fan on my gas furnace sounds like it is hitting other metal when it turns on or off. I had it serviced and he replaced the blower run cap but it has started again after about a week.
Could it be the furnace is not level? The service man said no that wouldn't do it but that's what it sounds like.
Best Answer
Of course it could be, but probably isn't. A spinning fan will hit anything in its path regardless of the relative direction of gravity.
I'd recommend calling your service person again for further troubleshooting.