I have two (2) Trane gas heater/blowers in my basement and one is completely silent when the blower isn't on and the other has hummed constantly for 10 years unless you turn the power completely off. I had some work done on my hot water heater and the plumber asked me why the blower unit was humming. I never gave a thought before because the heater always worked fine, no problems at all for 10 years, just the one unit hums and the other doesn't. The blower has a top and bottom half with two front panels to be removed. The hum is coming from the bottom section. There is an electrical box inside that has a lot of wires connected. If I push on that box I can change the sound of the hum, so I am fairly certain the hum is coming from inside that box (maybe?). The Plumber said it sounds like a soleniod or transformer hum.

Does anybody have a possible easy fix for this? I can turn off the electric open the box if need be.

Sounds like you have a 24 volt transformer that the plates are loose on. You cannot tighten them up. You have to replace the transformer if that is causing the hum.

It hums because it don`t know the words to song

Shame on me