Don’t you just enjoy the sound of that AC of yours on a sizzling afternoon? A quick hum starting out, and you are reassured that you will be cooler with that AC coming out of the air conditioning vents any moment. Then the constant hum of the outside heating and AC unit as it continues producing that frigid air. However, what would happen if that regular hum no longer sounded? If your AC stopped really working, and that hum is gone. I would first check the climate control unit to ensure no child of mine played with it while I was out. I would verify that the “cooling mode” was properly indicated on the control unit. If all is well at the climate control unit, I would then head over to the electrical box. If there had been a power surge while every one of us were in my absence from home, the breakers might need to be flipped off and back on again. I would not forget to check the air filter at this pressing time, just in case of a noticeable clog in the heating and AC system. If still, that regular AC hum is not heard, I would double-check the outside heating and AC unit to ensure that no tree limb had fallen on my unit. If it is all clear on the outside air conditioning equipment, I would have to call for an immediate heating and AC appointment. In this heat, I cannot stand to sweat and become irritated within my own home. Then I would have to go out to see a film and get some much-needed air conditioning until my AC maintenance specialist arrives.