I just bought a new Rheem condenser and air handler last week. After it was installed, I noticed a humming/buzzing sound coming from the air handler - which is in the attic. Should a brand new air handler be making this noise? It is not loud, but every time my wife and I walk by/just below the air filter, we hear it. I really don't want to hear this noise for the next 10 years. I had the rep come by and look at it to make sure his 3 Chuckle Heads installed it correctly, and he said Yes. He told me it was the transformer which is right against the fan housing that is making the noise. Should I be hearing this noise after buying a new unit? Thanks SO much for your help! Scott in Florida

Replace the transformer or you can try to insulate its mounting.