Waste Disposal Units

Expert Tips from FlowFix Plumbing in Orewa

Repairing and installing waste disposal units are part of our regular work at FlowFix Plumbing, so we know quite a bit about them.

How to make the most of your waste disposal unit

Waste disposal units, or InSinkErators® allow you to quickly and easily dispose of food waste right at your kitchen sink. Instead of having to put food scraps in a separate bin, you can simply rinse them down the drain, saving time and effort and reducing odours.

Food waste that goes to landfills produces harmful greenhouse gases, such as methane. If, like many of us in Auckland, you live in an area where kerb side compost pickup is still not available and you don’t have a compost bin, munching up food scraps in your garbage disposal is still better for the environment than tossing them in the rubbish.

However, like any appliance, food disposal units need to be installed by experts, used properly and undergo regular maintenance to keep working effectively.

waste disposal unit

A garbage disposal is not a rubbish bin

Firstly, and probably quite obviously, you shouldn’t just throw anything and everything down your waste disposal unit. While garbage disposals can handle quite a variety of food waste, it’s best to avoid overwhelming it with large amounts all at once. Instead, feed stuff down it gradually, in small chunks, so the unit can process it more effectively.

When you use your garbage disposal, we recommend you make a habit of running cold water for 15-20 seconds after you turn the unit off. This will help push all the waste through the pipes.

Avoid the hard stuff

Makers of more recent waste disposals say that it is fine to dispose of chicken bones, eggshells, some types of seafood shells, fruit stones, and other hard food scraps in their units. However, we suggest you don’t, particularly if your waste disposer is an older model. A garbage disposal is primarily designed for soft food waste. So, as a rule of thumb, we would say not to put hard or crunchy food scraps down the sink.

Biodegradable or water-soluble only

People are prone to putting stuff down the sink that really should be put in the rubbish, recycling, or compost bin.

Basically, most types of biodegradable food waste or items that are dissolvable in water are generally safe to put down the waste disposal unit. However, as with everything, there are a few exceptions.

What should you avoid putting down the sink?

  • Paper serviettes and paper towels. They may be paper, but many are treated or are too thick to be put in the wastewater system.
  • Cigarettes or cigarette butts
  • Fruit stickers
  • Tea bag strings

We also recommend taking care with the following:

  • Eggshells
  • Bones
  • Fibrous vegetables, such as celery, rhubarb, silverbeet, cabbage, corn husks, onion skins, or artichokes. These can wrap around the blades and impede their rotation, potentially leading to clogs or damage.
  • While small amounts of coffee grounds may pass through the disposal, it’s best to avoid throwing large quantities down. Coffee grounds can accumulate and form clumps, leading to blockages in drains or pipes.
  • Pulverised eggshells become sand like, settling at the bottom of pipes where grease can stick to them, clogging up the pipes.
  • Foods like pasta, rice, or bread should not be disposed of in large amounts. Starchy foods can swell or expand when exposed to water, potentially causing clogs or blockages.
  • Do not pour harsh chemicals or drain cleaners into them. As well as potentially damaging the unit, these chemicals pose a risk to the environment.

To need to keep your garbage disposal clean, smelling fresh and the blades sharp.

You can purchase commercial products to clean your unit. These include liquids you pour down and leave, foaming products that contain a degreaser, and various enzyme cleaners. However, product reviews and prices can vary greatly. We suggest, therefore, that you use products you already have at home, such as citrus, ice cubes, and vinegar.

  • Cut a lemon or an orange into wedges. Turn the tap on and drop the wedges down one at a time while the unit is running. The rinds clean while emitting a lovely fresh smell.
  • Drop in a handful of ice cubes followed by a cup of salt crystals. Turn on a small stream of water and let the disposal run until you can no longer hear the ice being crushed. Then, let the water run a little longer. As the ice grinds and melts, it not only sharpens the knives, but it also cleans sludge or particles off them. Two for one!
  • Cleaning the volcano method. Tip 1/2 cup of baking soda and a cup of vinegar into the disposal and watch the two ingredients go off! Leave it for 10 minutes, then run some hot water for a few minutes to flush everything through.
  • Once a month, fill your sink with hot soapy water. Then run the disposal unit to force the soapy water through the housing. This will help clean the nooks and crannies.

If you’re having issues, call FlowFix

If you notice any leaks, or strange noises or suspect that your unit is not working as well as it could, we can have a look at it and do what we can to keep it working effectively and safely. We will determine whether there are any blockages in the unit or the associated plumbing.

Installing a garbage disposal unit can be complex and requires specialised knowledge. You also need to be sure that your plumbing system is compatible. Older or inadequately sized plumbing systems may not be able to handle the increased load and flow rate of a garbage disposal. Check with our plumbers so we can make any necessary adjustments.

InSinkErator experts

Maintaining, repairing, and installing waste disposal units, particularly InSinkErator® models, is an area of expertise for us at FlowFix Plumbing. Over the years we have worked on numerous kitchen installations and renovations and have installed a variety of makes and models of food disposal units. There are a few trusted brands available, but at FlowFix Plumbing we only supply InSinkErator®. They have a sound reputation, a good range of sizes and models, and are easy to use and maintain. If you’re upgrading your kitchen, we’re also happy to advise on whether it’s worthwhile re-using your existing InSinkErator®. Get in touch for a no-obligation quote.

Call Colette today on 027 234 5454 or email the team.

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Contact Info

Our Office

Hatfields Beach, Orewa, Auckland

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M-F: 9am – 5pm


The FlowFix Plumbing team in Orewa are experts at repairing, supplying, installing and maintaining waste disposal units in Warkworth, Orewa, Whangaparaoa, Millwater and the North Shore of Auckland. To arrange a free, no-obligation quote,
please contact us today on
027 265 4949.