Turn off the 240-volt power at the appliance shutoff box. It’s usually outside within sight of the outdoor unit. Some shutoffs simply pull out; others have a handle to pull down or a fuse to remove.

One to two times a year, call up your local HVAC professional to take a look at your all-too-important AC coils. Cleaning AC coils costs anywhere from $75 to $700, or an average of $125 per coil. Dirt ...