I just had a new Rheem furnace installed but it makes a humming noise like a florescent light with a bad ballast. The noise level is such that if you don't know about it, you may not notice, but once you are aware of it, it is audible whenever in the garage. This noise is there as soon as the furnace is powered up, whether it is actually heating or not.
This is very annoying, it makes me think something is overloaded or there is a short circuit. But I wonder if I'm overreacting. The furnace works fine otherwise. I would like to do a poll before I call the heating company to complain because they may claim it is normal. My old furnace did not make any sound when powered up.