Garbage Disposal Maintenance Tips You Need To Follow

Posted by McCombs on 3rd Mar 2022

How to Keep Your Garbage Disposal Running Smoothly

Homeowners do not usually think about their garbage disposal when it’s working fine, but it is something that is impossible to ignore when it is broken. Of course, the most obvious consequence of a broken disposal is the fact that it can’t be used to dispose of food waste, which is a major inconvenience, but there are more serious problems that can result too. Broken garbage disposals can cause clogged drains, flooded sinks, and even mechanical or electrical problems that can potentially be dangerous.

That is why it is so important to practice proper garbage disposal maintenance. As the old saying goes, “an ounce of prevention is worth a pound of cure,” and that maxim applies to garbage disposals as much as anything else. Here is how to care for a sink garbage disposal:

Safety First

Many people have seen horror movies where victims get their hands pushed into a running garbage disposal, losing their entire arm in a shocking scene, but this is mostly just a Hollywood fiction. In real life, garbage disposals act more like dull grinders than sharp blades, and do not usually have the power to remove a finger – let alone an entire arm.

That being said, garbage disposal safety is still extremely important. As many homeowners and plumbers who have ignored basic safety measures can attest, garbage disposals can cause painful injury. You may not lose a finger, but people have gotten their hands cut and mangled before, requiring a visit to the hospital.

“There will be plenty of damage to the skin and bones without question,” says Wonderful Engineering. “Also, the injury can become fatal since there will be a good amount of bleeding involved.”

Even if the injury is light, bruises and scrapes are almost inevitable, and that is a risk that should be avoided. The biggest safety rule is also the simplest: do not ever put your fingers or hand in the garbage disposal. Even if the disposal has been unplugged or the circuit has been shut off, it is far from impossible to turn it back on by accident or fail to actually turn it off in the first place.

Put the Right Items Down the Disposal

The easiest and fastest way to break a garbage disposal is by loading it with food scraps or waste that it is not designed to handle. For instance, many people believe they should turn on the hot water tap while they run their garbage disposal, but this is a common misconception. The truth is that hot water can cause the garbage disposal motor to overheat, especially when it is run for a long time. Running cold water the whole time is necessary, and hot water does not help keep the disposal clear; in fact, it makes it more likely to break over time. Cold water has the unique benefit of solidifying grease and fatty waste, turning them into chunks that can be broken down by the disposal instead of a liquid that will flow into the pipes and clog them later.

It is also important to note that most common disposals can only handle about one cup of waste at a time, so don’t exceed that. The most common cause of garbage disposal problems is “operator error,” so make sure to treat the disposal with the care it requires. Putting too much waste in, trying to force something through that the disposal cannot handle, or using the wrong tools to clear clogs and jams can cause serious problems.

What Can You Put Down the Garbage Disposal?

  • Small pieces of food. Tiny scraps of food left on the plate after a meal is what a garbage disposal is intended for. Avoid large amounts of food waste or big chunks If it’s bigger than a marble, it is too big, and it is best to limit food chunks closer to the size of a pea.
  • Breads. Breads break up easily and dissolve quickly in water. Use plenty of water to avoid the bread turning into a paste that will gunk up the disposal, and never try to put large pieces or loaves of bread in.
  • Cooked meat or vegetables. Most cooked vegetables and meats are soft enough to grind up in the disposal with ease, but it is important to avoid loading in bones, husks or rinds, or stringy produce.
  • Egg shells. Although many people believe egg shells are not okay to put in because they aren’t water soluble, they break up easily and do not build up in the drain. As long as you keep the egg carton out of the drain, you should be fine.
  • Ice cubes or rock salt. Putting ice or rock salt in the drain makes an awful noise, but it is okay to put them in the disposal. In some cases, the ice or salt may rumble around and scrape things off the disposal, helping it to stay clean. However, these materials do not sharpen the blades, contrary to popular belief.

What Can’t You Put Down the Garbage Disposal?

  • Bones, fruit pits, or small pebbles. This will cause severe blade damage and clog your drain. The general rule of thumb is that you anything you can’t chew up yourself should probably not go into your garbage disposal.
  • Grease, oil, or greasy foods. Oil and water don’t mix. Fatty foods or grease don’t either, and although garbage disposals can handle a small amount of these materials, large quantities will cause clogs and gum up the blades.
  • Dry rice or pasta. Large quantities of dry rice or pasta can soak up water and expand in the pipes, causing severe clogs.
  • Stringy vegetables. Things like celery or asparagus can wrap around the blades and stop them from spinning, which will require significant work to untangle and fix.
  • Fruit peels or rinds and vegetable husks. Although the interior of most fruits and vegetables are disposable, the exteriors are much tougher than many people think. Don’t underestimate nature. A small amount is usually okay, but large quantities are a surefire way to clog the disposal, and can even damage the blades.
  • Coffee grounds. These are one of the most common causes of disposal clogs, and many people have gotten lucky enough trying to load their disposal with coffee grounds that they think it will work every time. Spoiler alert: it won’t.
  • Your hand. As discussed above, this is a major safety hazard – even if you think the disposal is disconnected.
  • Shrimp shells, stems, silverware, artichoke, rocks, jewelry, wood, and other hard materials.

Know Your Disposal

There are several different types of garbage disposal used commonly in homes and businesses. The two most common are batch feed and continuous. Batch feed garbage disposals requires a cover to be placed over the drain opening to activate the disposal, after which it processes the “batch” of waste under the cover. Continuous garbage disposals use a simple switch to turn on and off, and can (theoretically) run continuously as they are fed a steady stream of waste. There are many other types, such as air switch models that use air to activate, but they all have one thing in common: their power feed. Almost all non-industrial disposals have a power feed coming from an outlet under the sink or very close nearby.

If you aren’t sure what type of garbage disposal you have, you can check under the sink to look for a tag that should include the model number (this video is a great guide). After finding the tag and the information on it, all it takes to identify the type of disposal is a quick Google search.

For safety reasons, never work with the power to the disposal on. It is a good idea to check the power to the switch (for continuous garbage disposals) using a voltage tester, after unplugging the unit. This is also great way to determine whether a problem originates from a tripped or faulty breaker and identify possible electrical problems.

Keep it Clean

Even if the garbage disposal is working, it is still important to perform regular cleaning and maintenance to ensure it stays that way. Although this will never completely guarantee the disposal survives for its expected lifetime, it will certainly help. At the very least, it prevents nasty bacterial smells from building up, and helps to prevent pests like fruit flies, cockroaches, and silverfish from feeding or breeding in the drain. Cleaning a garbage disposal should be done at least once every week or two, depending on the frequency of use and what materials it processes.

First, turn the disposal off and disconnect it from its power source. It is best to also flip off the switch connected to that part of the kitchen on the circuit breaker and test the power switch to ensure there is no electricity going to the disposal. Using a flashlight, look down the drain and check to see if there are any objects trapped in the grinder. Clear any blockages with a wire, tongs, or a long-nosed pair of pliers. Again, never put your hand in.

After reconnecting the power supply to the disposal, plug the sink and fill it half full of warm (not hot) water. Pull the plug and turn the disposal on until all of the water has flushed through. Turn the disposal off disconnect the power a second time.

Use a long-handled scrub brush with a small, flexible head to scrub the inside of the disposal. Many people find an old toothbrush works fantastically well for this job. Get the brush head wet with warm (not hot) water and put in a little bit of strong, grease-targeting dish soap. Make sure to reach all of the surfaces on the inside of the disposal. When finished, reconnect the disposal and clear it using the method described in the paragraph above.

Having now gotten most of the waste off, it is time to get rid of lingering bacteria, mildew, soap scum, water deposits, and grime. First, sprinkle half a cup of baking soda – not baking powder – or washing soda into the opening of the disposal. Pour in one cup of white cleaning vinegar (or two cups, for washing soda) and let it soak for around 10 minutes. It is normal for the mixture to bubble from the chemical reaction that takes place.

Addressing Common Disposal Problems

Here are some of the most common garbage disposal problems and how to fix them:

Garbage Disposal Doesn’t Turn On

    If the garbage disposal does not run when the switch is flipped on or the lid is put on (for batch feed disposals), there is most likely an electrical issue that is stopping the appliance from getting power. To figure out what the problem is, and how to fix it, follow this guide to begin with the likeliest cause and easiest solution and work through the list to the more complex issues:

  • Make sure the garbage disposal is plugged in. This may seem incredibly obvious, but many appliance company customer service centers have reported that the appliance being unplugged is the most common single cause of problems. It happens to the best of us. Check if it is plugged in, and if it is, move on to the next step.
  • Press the reset button located on the bottom of the unit. Almost all garbage disposals have a red reset button that is built in to serve as a circuit breaker. If the reset button has been tripped, it will be popped out slightly. All it takes to reset the disposal is pushing it back in. Check the button and try to press it, then test the disposal. If pressing the red reset button doesn’t do the trick, then move on to the next step.
  • Check the building’s main service panel to determine whether the circuit breaker has been tripped. If it has been tripped, reset the circuit breaker and test the disposal. If that does not successfully fix the problem, move on to the next step.
  • Check for wiring problems. If neither the main circuit breaker nor the garbage disposal reset button are causing the problem, then it is possible that the problem originates in wiring problems with the switch controlling the disposal, or that the disposal itself is malfunctioning. To fix this (for a continuous feed disposal) find the switch that powers the disposal. This can be found on the wall most often, or sometimes under the sink. Then, go to the building’s main service panel and turn off the circuit breaker switch that provides power to the disposal circuit. Once the power supply is cut, take apart the switch controlling the disposal. Look closely at the wire connections. Sometimes, the problem is caused by something as simple as a loose wire connection, and the fix is as easy as tightening the connection at fault. If the wire connections are secure, then move on to the next step.
  • Replace the switch. Assuming the wire connections are not at fault, the problem is likely in the switch. Turn the power back on and test the disposal to see if that works.

If none of those steps solves the problem, the garbage disposal itself is likely broken and irreparable, and it will need to be replaced. If a new disposal does not work, it is time to call a qualified electrician or plumber to have a look.

The Disposal Makes Noise Without Running

If the garbage disposal will not fully run to grind waste but the motor makes an audible humming noise when turned on, the problem is likely a jammed flywheel. Usually that causes the disposal reset button to pop or the circuit breaker to trip very soon. Note that running the disposal in this situation can burn out the disposal’s motor very quickly unless the circuit breaker or reset button turns it off.

Jammed flywheels are usually caused by food or some other object getting lodged between the shredder ring and the impeller inside the disposal. Turn the power supply to the disposal off at the service panel by turning off the breaker that powers the circuit feeding the disposal. Turn off the wall switch controlling the disposal, too.

Then, use a flashlight to peer down into the disposal through the drain opening. If the object causing the jam is visible (most often materials like meat bones or silverware), remove it using tongs or a long needle-nose plier. Try moving the flywheel, and if it moves freely the problem is probably fixed.

Next, locate the offset wrench that came with the disposal unit. If the original offset wrench is not available, a replacement wrench can be purchased very cheaply from whatever hardware store sells that garbage disposal model. Often, a large Allen (or hex) wrench will do the trick. Whatever the case, once located, insert the wrench into the flywheel turning hole at the bottom end of the disposal unit. Turn it clockwise to unjam the stuck flywheel. Once the jam is dislodged, there will be a noticeably freer range of motion in the flywheel.

Alternatively, sometimes it works to simply use a wooden spoon handle (never insert metal silverware) and stick it in the disposal through the drain opening and force the disposal flywheel to move. If that works, there will be a noticeably freer range of motion in the flywheel in the same way as above.

When the flywheel is moving freely, turn the power on at the building’s main service panel – but do not turn the disposal on. Press the red reset button on the bottom end of the disposal first, then run some cold tap water into the disposal and rapidly flip the disposal power switch on and off. Do this several times in short bursts. This spins the flywheel and allows any additional debris to get washed down the drain.

The Disposal is Leaking

Leaks in garbage disposals can happen in a variety of different places on the unit. The most common leak locations are:

  • The sink flange (where the bottom of the sink connects to the garbage disposal unit)
  • The hose connecting the dishwasher to the disposal
  • The hose that discharges the processed waste from the disposal into the sewer system

If the leak is coming from the sink flange, it is probably the result of constant vibration from the disposal unit gradually loosening the mounting apparatus that holds the disposal on to the sink drain opening. The sink mounting flange is the most common place for disposal-related leaks, but it can be fixed rather simply.

First, turn off the power to the disposal at the building’s electrical service panel by switching off the circuit break that controls it. Then, at the disposer mounting ring beneath the sink, turn the disposal counter-clockwise (from the bottom) to loosen the unit. Keep twisting until the unit can be removed from its mounting flange. Once it is off, use a wrench to check the mounting bolts holding the flange to the sink; there are usually three bolts but the number can occasionally be different. If the bolts are tight, a leak is probably the result of failed or expired plumber’s putty. Loosen the bolts a little bit and push the sink flange a little bit above the sink surface. With a fresh tube of plumber’s putty, squeeze a bead between the sink and the sink flange. Go all the way around the flange. Tighten the mounting bolts back in, while drawing the sink flange tightly against the sink surface. If that causes putty to drip out, use a paper towel to wipe away the extra putty. Reinstall the disposal with the mounting ring – go clockwise this time – and turn the power back on at the building’s electrical service panel. Run water through the sink, and check if that causes any leaks. Assuming that goes well, try running the disposal with the water flowing and check for leaks, as a sort of “stress test.”

If the leak is coming from the dishwasher connection, the (usually rubber) hose that directs wastewater from the dishwasher to the garbage disposal unit, checking does not require a complicated series of steps. Simply tighten the clamp of the dishwasher hose that is connected to the dishwasher inlet on the disposal. If that does not fix the problem, the hose needs to be replaced, and whichever hardware store or company sold the unit can probably provide a replacement hose.

If the leak is coming from the discharge drain pipe, the (usually plastic) pipe that transfers wastewater from the disposal to the sink drain trap, the leak probably began when the gasket gets old. Using a wrench, check the bolts that hold the discharge pipe up to the disposal. Make sure they are tight because loose bolts can cause the leak, but assuming they are tight, remove the bolts and the pipe. Then, replace the gasket seal between the garbage disposal unit and the pipe. Reinstall the bolts and tighten them. If the leak persists, it is time to call a plumber or get the appropriate replacement appliances.

The Disposal Drains Slowly

One of the most common garbage disposal problems is slow draining. This can be caused by a wide range of different issues, but there is a lot of overlap with the ordinary problems that lead to clogging. In general, the solution to this problem is disassembling the discharge pipe and the drain trap, removing the food waste clogging up the pipes, and then reassembling the system and testing it.

To do this, first remove the bolts that hold the discharge pipe up to the garbage disposal unit. Disconnect the drain trap, remove it, and remove the discharge drain pipe. Inspect the components for any sort of obstruction or blockage that might be causing the slow draining. If there are no obvious and visible obstructions, the clog is most likely in the branch drain line that goes into the wall. You can clear that obstruction with a sink auger. Wherever the clog is, once it is removed, put the drain trap back together and reconnect the discharge pipe to the garbage disposal unit’s side port. Run the cold water tap, turn the garbage disposal on, and test how well it drains out of the sink.

Many people opt for strong chemical drain cleaners, but these may not be a good idea. First of all, chemical drain cleaners are often ineffective and unsafe. If not handled properly, they can be toxic and cause serious chemical burns to skin, eyes, or lungs (if they produce caustic vapors). Each type of chemical drain cleaner only works for a limited range of clog types, and in most situations they will not be much help. But more specifically, these harsh chemicals can damage the garbage disposal unit and, in some cases, using them will void the manufacturer warranty.

The Disposal is Too Loud

Although some level of noise is usually an acceptable price to pay for the convenience of having a garbage disposal, it can become pretty obnoxious is the noise becomes excessive. Unusual noises coming from the disposal such as humming, sputtering, or clacking can also be a cause for concern. These noises can make an appearance when something is wrong with the garbage disposal, so it is important to consider other potential issues before jumping to any conclusions. That being said, it is helpful to look at the possible noises and how to address the problems they might be symptoms of. If the disposal is making a humming or whirring noise, the most likely explanation is that something has gotten jammed in between the disposal’s impellers and shredders ring. The solution to this problem is mentioned above, but the short version is that it needs to be cleared and possibly disassembled first. Remember to turn off the disposal, unplug it, and go to the building’s electrical control panel to shut off the power to the appropriate circuit. Another common cause, which is also addressed above, is a malfunctioning flywheel. However, if the noise is a loud rattling or grinding noise, it is probably a foreign object getting thrown around by the garbage disposal’s impellers. If this is the case, turn off the disposal immediately since the foreign object could be damaging the unit. Unplug the garbage disposal, and just to be safe, go to the building’s electrical control panel to shut off the power to the appropriate circuit. Since the object is probably loose and not jammed in the disposal, it will be easiest to remove with tongs or some other tool (never put your hand in the garbage disposal). If you are not able to locate the object responsible, it is possible that the impellers of the garbage disposal itself have become loose and are clanking around. Sometimes the metal bolts that hold the impellers down can be loosened by the vibration of the disposal while it runs over time. This can be addressed by tightening the bolts (there are usually two of them) holding the impellers to the unit. If the noise is more of a squealing sound, then it may be symptomatic of a bigger issue. Turn off the disposal the second it makes any squealing noise and immediately unplug it. This could be a sign that the motor of the unit is dying, and it could be a sign that it is time to purchase a new garbage disposal. There are many steps you can take to reduce noise, though, so don’t give up if it’s just a volume issue. “You might be surprised, but not all garbage disposals are loud,” says Quiet Household. “Garbage disposals with as much as one horsepower can produce noise under 45 decibels.”

Get a New Disposal

Sometimes, it’s easier to just get a new disposal. For instance, if a garbage disposal is too loud, one simple solution is replacing it with a model that makes less noise. There are also models designed to remain sanitary and not generate foul odors, models designed to prevent clogging and jamming, models designed to handle larger loads of waste than ordinary disposals, models designed to drain quickly, models designed not to leak, and models designed for a wide range of other purposes.

To look at these models, and many other appliance models, have a look at our catalog.

Recent Posts