A garbage disposal is an essential appliance in most kitchens that helps shred and grind food waste to keep drains running smoothly. While garbage disposals are generally reliable, they contain multiple components that can wear out over time and require repair or replacement. Understanding the anatomy of a garbage disposal and the function of each part is helpful for proper maintenance and troubleshooting issues when they arise. This visual guide provides an in-depth look at the various internal and external components of a typical garbage disposal unit.
How a Garbage Disposal Works
Before diving into the specific parts, it’s helpful to understand the overall operation of a garbage disposal. When the disposal is turned on, an electric motor spins a turntable at the bottom of the unit. This turntable contains swiveling plates known as impellers or lugs that fling food waste against a stationary shredder ring. The ring has grinding edges that pulverize the food particles as they are propelled against the ring surface. Once broken down into tiny fragments, the food particles are flushed through the disposal drain outlet and into the home’s plumbing system.
The key components that make this grinding and draining process possible include:
External Components
Sink Mounting Assembly
This section connects and locks the garbage disposal unit to the sink opening. It consists of:
- Sink flange: Also called the sink adapter or mounting flange, this ring-shaped component fits over the sink drain opening and provides a seal between the disposal unit and the sink. It has mounting ears with holes to accept the mounting bolts.
- Mounting ring: This backup ring fits under the flange and distributes the clamping force so the flange forms a tight seal on the sink without cracking it. Some models have the mounting ring integrated with the sink flange.
- Mounting bolts: These bolts pass through the mounting ears on the sink flange and thread into the mounting ring or disposal collar to lock the unit firmly onto the sink drain. The bolts are turned opposite directions to tighten or loosen the connection.
Discharge Tube
The discharge tube, also called the elbow, fits over the disposal outlet and connects to the downward drainpipe that leads to the trap and plumbing system. A watertight gasket seals this connection. The elbow is usually made of durable plastic and can rotate 360 degrees to align with the drainpipe.
Disposer Collar
This is the uppermost external component that connects the mounting assembly to the body of the disposal unit. It has threaded holes to accept the mounting bolts. Turning the bolts draws the sink flange and collar together to create a tight mount.
Reset Button
Many models have a small external button that can be pushed with a broomstick or other tool to manually reset or restart the disposal if the motor becomes jammed or overloaded. This button pops out if the unit overheats. Pressing the reset button allows the motor to operate again once the jam is cleared.
Internal Components
Grind Chamber
This is the open space inside the unit that collects food waste dropped from the sink opening. It surrounds the upper part of the spinning turntable. Splash guards along the top opening prevent water and debris from spraying out. The grind chamber walls contain slots around the perimeter where ground particles exit to the disposal outlet.
Turntable Assembly
Centered below the sink drain opening is the turntable component. It consists of:
- Turntable: Also called a swivel impeller plate, this disk-shaped part spins when the motor operates. Food waste drops onto the turntable surface.
- Impellers: These swiveling lugs mount to the top of the turntable plate and fling food particles against the grind ring. The number of impellers varies based on disposal model and power. More impellers provide faster grinding capability.
- Center cone: A cone-shaped projection below the turntable mounts onto the motor shaft. This is the point where the spinning action originates.
Grind Ring
This is the stationary ring that surrounds the turntable assembly and provides the fixed grinding edges. Various grind ring designs and materials are used, ranging from basic molded plastic to advanced metal alloys. As the impellers fling food waste outward, the particles strike the textured grinding surface and are pulverized into tiny fragments that can pass through the disposal drain system. Some models have a double grind ring design with two separate grinding stages.
Motor
The electric motor powers the spinning action of the turntable. Garbage disposal motors operate at high speeds ranging from 1,700 to over 2,800 RPM. Higher speeds provide greater grinding capability. Motors are rated by horsepower, with popular models typically between 1/3 and 1 HP. More powerful motors can grind tougher waste but tend to be louder in operation. The motor is equipped with a manual reset mechanism in case of jams.
Wiring
A power cord with a plug connects the motor to the electrical supply under the sink. A manual wall switch near the sink provides convenient on/off operation. The wall switch and disposal are wired together with electrical cable and wire nuts. For safe operation, the unit should be on a dedicated 15-20 amp circuit with a GFCI for protection against shocks.
Key Garbage Disposal Parts and Components Visual Guide
Here is a summary visual guide to the location of the main garbage disposal components described above:
Typical Garbage Disposal Problems and Solutions
Understanding how the internal mechanisms work together helps troubleshoot common garbage disposal issues when they arise. Here are some typical problems and potential solutions:
Disposal hums but does not spin:
- Potential issue: Jammed impellers or foreign object lodged in unit.
- Solution: Disconnect power, check for and remove obstruction, reset impellers, push reset button if available.
Leaking from the bottom:
- Potential issue: Damaged or leaking gasket seal.
- Solution: Tighten drain connections, replace gasket seal if worn.
Loud grinding or rattling noise:
- Potential issue: Hard object such as spoon or bottle cap stuck in unit.
- Solution: Unplug disposal, remove obstruction, press reset button.
** circuit trips during use:**
- Potential issue: Overloaded circuit or faulty wiring.
- Solution: Ensure disposal is on dedicated 15-20 amp circuit, check and correct wiring connections.
Intermittent starts and stops:
- Potential issue: Overheating motor or thermal overload trip.
- Solution: Let unit cool completely, press reset button, monitor use to prevent overloading.
Weak grinding performance:
- Potential issue: Worn impellers or grind ring.
- Solution: Replace impeller kit and inspect grind ring for excessive wear.
Tips for Proper Garbage Disposal Maintenance
To keep your garbage disposal operating at peak performance and extend its overall service life, follow these important maintenance tips:
- Run a strong flow of cold water before, during, and after using the disposal to help flush waste through the system.
- Feed food waste slowly into the disposal; don’t overfill.
- Cut or break up large items prior to disposal.
- Avoid putting hard or dense objects down the unit.
- Grind citrus peels or ice cubes periodically to polish and sharpen the grind ring.
- Every few months, pour a 50/50 vinegar and water mixture into the unit while running to flush and deodorize.
- If not used often, fill disposal with water and run it regularly to prevent rusting.
- Check sink drain connections for leaks and tighten mounting assembly if needed.
- Replace the sink flange seal if leaking occurs around sink opening.
- Inspect impellers for debris buildup and visual signs of wear. Remove and clean as needed.
- Have grinding components professionally inspected/replaced every 5-10 years.
When to Call a Repair Service
While regular upkeep and minor troubleshooting can be performed by a homeowner, certain garbage disposal repairs are best left to professionals:
- Major motor repairs or replacements
- Extensive wiring diagnostics and repairs
- Repairing leaks from metal components
- Installing a completely new garbage disposal
- Any repair that involves directly accessing grinding components while energized
- Electrical short circuits or shocks while operating unit
For major repairs, it is advisable to call a certified plumbing appliance repair technician to properly diagnose issues and fix or replace components. They have the skills, experience, and tools to safely service garbage disposals.
Frequently Asked Questions About Garbage Disposals
Here are answers to some common questions about garbage disposal units:
What items should never be put in a garbage disposal?
Avoid putting anything fibrous (corn husks, artichokes), hard (bones, shells, glass, pennies), greasy (butter, oils), or non-food items (sponges, plastics) down the garbage disposal. These can clog drains or damage components.
How can I clean and deodorize my garbage disposal?
Grinding citrus peels or ice helps polish and freshen a disposal. For thorough cleaning, flush with a 50/50 white vinegar and water solution. Baking soda can also absorb odors. Avoid chemical drain cleaners.
Why is my garbage disposal leaking from below?
A leak from the base likely indicates a problem with the discharge tube gasket seal. Try tightening connections. If the leak persists, the gasket probably needs replacement, which is a job for a professional.
How do I unjam a stuck garbage disposal?
Use a hex wrench or special jam-clearing tool to rotate the turntable and dislodge stuck debris. With the power off, you can try removing the splash guard and physically removing debris blocking the turntable. Press reset button when complete.
How can I make my garbage disposal quieter?
Check for debris stuck in grinding components. Install a sound dampening gasket or quiet collar around the sink opening. Have motor mounting bolts tightened. Upgrade to a quieter premium model if noise persists.
Why does my disposal keep tripping the circuit?
Frequent circuit overload trips usually indicate the disposal is on an insufficient amperage circuit and needs to be moved to a dedicated 15-20 amp circuit. Faulty wiring connections can also cause tripping issues.
When should I replace vs repair my garbage disposal?
If repairs exceed 50% of the cost of a new unit, replacement is usually better. Replacement may also be preferable if the disposal is over 10 years old or repair parts are no longer available.
Conclusion
Knowing the detailed internal workings of a garbage disposal enables easier troubleshooting when problems arise. Regular maintenance and inspection will also help prevent costly repairs. If major work is needed, don’t hesitate to call a professional repair technician. Following the proper techniques for grind component cleaning, jam-clearing, and leak detection will help keep your garbage disposal grinding smoothly for many years. With routine care, your disposal will remain an essential and convenient kitchen appliance.