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Ironwood ValleyPlumbing · Surprise, AZ
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Questions · Drains and sewer

What should never go in a garbage disposal

Grease and oil, coffee grounds, eggshells, rice and pasta, fibrous vegetable skins, bones, and anything stringy. A disposal grinds; it does not make food vanish. What it grinds still has to travel down a kitchen line that is already the greasiest pipe in the house.

Last updated September 2026Ironwood Valley Plumbing
New garbage disposal and drain trap under a kitchen sink
Garbage disposalBuckeye 85326

The list

  • Grease, oil and fat, which cool and coat the pipe further down
  • Coffee grounds, which pack together like wet sand
  • Eggshells, which shred into fine grit that settles
  • Rice and pasta, which keep swelling after they are ground
  • Celery, artichoke, corn husks and onion skins, which wrap around the impellers
  • Bones and fruit pits, which the unit was never made for
  • Anything not food: bottle caps, twist ties, silverware

How to run it so it lasts

  1. 01

    Run cold water before, during and for a good while after, so what is ground actually travels

  2. 02

    Feed it a little at a time rather than filling the chamber and switching on

  3. 03

    Keep grease out of the sink altogether: let it set and throw it away

  4. 04

    If it slows or sounds different, stop and look before pushing more through

Why cold water, not hot

Hot water melts fat, which then travels a short way down the line and cools on the pipe wall. Cold water keeps it firm so it is carried out with everything else. It is a small habit and it is the difference between a kitchen line that stays clear and one that slowly closes up.

Answers

More on this

Is my disposal broken or just jammed?

A hum with no turning is usually a jam. Silence with nothing at all is usually power or the reset. Both are worth checking before anyone replaces a unit.

Do ice cubes sharpen the blades?

There are no blades, there are impellers that throw food against a grind ring. Ice knocks debris loose, which is useful, but it is cleaning rather than sharpening.

Can a disposal cause a main line problem?

It can contribute. Everything it grinds joins the same drain, so a kitchen line that is already coated will catch that much sooner.

If you need this done

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