While the drain connection for a garbage disposal is nearly universal and fits standard sink drain holes of 3 1/2 to 4 inches, the size of the disposal unit itself is not. You must have enough space in the cabinet underneath your sink to accommodate the disposal's housing. A larger model may not fit in a compact cabinet or if the existing plumbing is arranged in an unusual way. Before buying a new garbage disposal, measure the available space under your sink. If you are replacing an old unit, it's often easiest to choose a new model of a similar size.

If your garbage disposal powers up and you can hear it hum, but the arms inside aren’t moving, the problem might be a stubborn clog, a build-up of grease, or a jam of the impeller plate. To troubleshoot these, ensure your unit is off and disconnected from its power source before checking inside the drain or attempting to manually rotate the impeller arms or plate from the underside of the unit. A hex wrench can help.

To prevent drain clogs, perform regular maintenance and cleaning. Avoid disposing of substances like grease or coffee grounds down the sink. Additionally, installing and routinely using drain strainers can help catch debris and prevent blockages from forming.

Garbage disposals are durable appliances that usually last at least eight years as long as you clean and maintain them. It’s relatively rare for a garbage disposal to break on its own, as most malfunctions happen due to user errors, like overstuffing the grinding compartment or damaging the blades by trying to dispose of metal or bone. Eventually, cracks or leaks could develop in the unit, which requires a full replacement.