Your air conditioner's humming sound could be a sign of a damaged capacitor. It is possible for them to fail within five years, so regular maintenance isn't possible. To determine if there is a problem with a capacitor examine for signs of corrosion on the capacitor's wires and for leaks at connections to copper tubing of the coil's outdoor side. They are most probable to cause the cause, so you will need to charge your system.

If you're not sure if you're dealing with a blockage in…