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Garbage disposal instructions

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10-26-2010 , 01:14 AM

Aaron W.

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I had my garbage disposal replaced today, and I was looking at the operating instructions:

Quote:

Don't use hot water when grinding food waste.

Why not?

My best guess so far is that it has to do with foodstuffs being more pliable when hot, and therefore the grinding action is less effective, but this seems dubious to me.

Anyone with any other ideas?

Edit: The unit was replaced for leaking, not motor failure. So now I have 1/2 horsepower electromagnetic motor that I don't want to throw away, but I also don't know what to do with it...

Last edited by Aaron W.; 10-26-2010 at 01:21 AM.

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10-26-2010 , 01:20 AM

ZeroPointMachine

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Because once upon a time a piece of food spinning in the disposal splashed hot water into someones eye.

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10-26-2010 , 01:29 AM

All-In Flynn

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IME weird instructions, rules and restrictions like that are indeed often the result of insurance requirements.

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10-26-2010 , 01:32 AM

Aaron W.

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Quote:

Originally Posted by ZeroPointMachine

Because once upon a time a piece of food spinning in the disposal splashed hot water into someones eye.

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Originally Posted by All-In Flynn

IME weird instructions, rules and restrictions like that are indeed often the result of insurance requirements.

I sort of figured that if this were the case, then it would be in the "WARNING: DON'T BE AN IDIOT" section, where it tells you not to put metal and ceramics into your garbage disposal.

But it's possible that you're right and this has nothing to do with the functioning of the machine itself.

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10-26-2010 , 01:39 AM

guesswest

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Join Date: Dec 2005 Posts: 2,998

Limescale?

I think you should create a second thread requesting ideas for things to do with the motor, that could be a good thread.

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10-26-2010 , 01:43 AM

guesswest

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Join Date: Dec 2005 Posts: 2,998

I just googled this and apparently the reason is that hot water can melt fat which might then solidify in the pipes and cause blockages.

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10-26-2010 , 11:55 AM

durkadurka33

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Quote:

Originally Posted by ZeroPointMachine

Because once upon a time a piece of food spinning in the disposal splashed hot water into someones eye.

This is far too plausible...

Why do coffee cups have the word HOT!!! on them?! Cuz some ****** sued for being ******ed..."what a country!"

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10-26-2010 , 03:34 PM

BruceZ

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It's to keep the motor from overheating.

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10-26-2010 , 06:10 PM

Aaron W.

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Quote:

Originally Posted by BruceZ

It's to keep the motor from overheating.

I thought about that one, but after dismantling the unit, I don't think this is plausible.

This appears to be the motor type: http://en.wikipedia.org/wiki/AC_induction_motor

Using this image as a guide:

http://en.wikipedia.org/wiki/File:Ga...al_innards.png

The coils are located at #31, and there is a decently large physical gap between the coils and the water flow (#35 = exit port). Unless you're pouring gallons of boiling water down the drain, I don't think that there will be a significant heat transfer from the water to the coils.

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10-26-2010 , 06:29 PM

#10

All-In Flynn

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I think guesswest is probably on the money here. The fact that Aaron notes the instruction is separate from other 'Do not insert hand in unit while motor is running'-style caveats seems fairly significant to me.

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10-26-2010 , 08:55 PM

#11

BruceZ

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Quote:

Originally Posted by Aaron W.

I thought about that one, but after dismantling the unit, I don't think this is plausible.

I have always used cold water, and the overheating issue has always been the reason. Here is a professional plumbing site that supports my position. Here is an appliance repair site that says:

"Also, cold water helps cool the motor; whereas hot water can so raise the temperature that it can cause the motor to burn out. So beware of hot water and make sure you never use it again. You don’t want to ruin the garbage disposer motor, because replacing it can turn out to be a lot expensive than you can think."

It is true that the stator coil windings are separated from parts that touch the water. Electric current also flows through the rotor which is directly connected to the moving parts that do touch the water; however, I couldn't find you evidence that rotor winding burnout is a significant problem with these types of motors.

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Unless you're pouring gallons of boiling water down the drain, I don't think that there will be a significant heat transfer from the water to the coils.

Many people have their water heaters set so high that this isn't far from what happens.

Last edited by BruceZ; 10-26-2010 at 09:06 PM.

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