Any Idea why my garbage disposal gets too hot to touch when running the dishwasher? This is in a relatively new home. We’ve only used the dishwasher a dozen times. It started to stop mid cycle and while checking things out I noticed the garbage disposal is burning hot. You cannot even touch it without burning yourself. The red reset button is tripped and cannot be pushed back in until the disposal cools off. I called the builder to inquire about this and they suggested it is a faulty disposal. So now I’m not sure if I call a plumber to install a new disposal or an electrician to check if something is wired incorrectly. Any suggestions would be greatly appreciated. Thanks in advance!
Garbage disposal overheats when using dishwasher
- Thread starter Lori
- Start date
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Running the dishwasher shouldn’t make the disposal hot and shouldn’t make the reset pop.
Its possible the discharge water of the dishwasher could make the disposal warm if it drains through it, but not hot.
Any lightning in the area recently ?
Its possible the discharge water of the dishwasher could make the disposal warm if it drains through it, but not hot.
Any lightning in the area recently ?
Can you remove the strainer, splash guard if you will, from the sink and put your hand down the disposal and see if it turns freely by hand? (NOTE: DO THIS ONLY AFTER YOU OPEN THE BREAKER TO THE DISPOSAL!) If it doesn't turn freely I suspect the motor and/or bearings have begun to freeze up. I don't think it's a wiring error at all. Get the builder to honor the warranty.
What Mr. Twowax says is spot on as well!
What Mr. Twowax says is spot on as well!
Jeff Handy
Pro Handyman, NOT A Pro Plumber
Don’t ever stick your hand in, use a wood stick or broom handle or wood spoon to try to rotate it.
Or turn off the breaker, if you are 1000 percent certain it is the right breaker.
If you are wrong, you can lose fingers.
But it sounds like a wiring problem, not a bad disposal.
Unless your water heater is set to a crazy high temperature.
Also, if your dishwasher and disposal are on the same breaker, do not operate both at the same time, because that can overload the circuit.
Or turn off the breaker, if you are 1000 percent certain it is the right breaker.
If you are wrong, you can lose fingers.
But it sounds like a wiring problem, not a bad disposal.
Unless your water heater is set to a crazy high temperature.
Also, if your dishwasher and disposal are on the same breaker, do not operate both at the same time, because that can overload the circuit.
Has it been your experience that the disposal worked properly at all or has it always exhibited this overheating condition? If at one time it worked properly and it has only recently started to overheat and pop the overheat protection mechanism, that would indicated that it was properly wired and something in the disposal itself has changed over time.
Jeff Handy
Pro Handyman, NOT A Pro Plumber
Yes, the disposal might be jammed.
But the switch for it might still be in the ON position.
When you push the RESET, it tries to operate but is jammed, so it just heats up.
Keep your hands out of there!
Does the disposal even operate, or not?
But the switch for it might still be in the ON position.
When you push the RESET, it tries to operate but is jammed, so it just heats up.
Keep your hands out of there!
Does the disposal even operate, or not?
I am in violent agreement with most of what you recommend. Most disposals have some sort of access panel at the bottom of the disposal that allows access to the rotating mechanism for use of a wrench or something to physically turning the motor and clearing a jam. My ISE does and this one probably does too. If the unit rotates at all, it's not jammed and the bearings have begun to seize.
Per my original recommendation, if you can confirm that you have removed all power to the unit there is no issue with putting your hands in the disposal. If you can't confirm that you've removed the power then don't.
Per my original recommendation, if you can confirm that you have removed all power to the unit there is no issue with putting your hands in the disposal. If you can't confirm that you've removed the power then don't.
Mitchell-DIY-Guy
Well-Known Member
If I read this correctly @Lori indicated that the dishwasher stops mid cycle, and when this has happened, the disposal is hot?
Here in NC, a single 3-wire is run from the service panel to a junction box in the crawl space where it separates into two lines, one for the dishwasher and one for the disposal. The neutral is shared, and at the service panel the breakers are separate but tied together. So if either dishwasher or disposal trips a breaker both shut off.
Just a guess here but the disposal is tripping either a shared or connected breaker.
Should be a very easy diagnosis for someone on-site.
If the house is less than a year old, it’s the builders responsibility. Maybe the disposal itself has a longer warranty BUT if so, someone has to remove it, follow warranty claim instructions and sadly have a second unit ready to install immediately. Cannot leave a non-functioning sink…
Here in NC, a single 3-wire is run from the service panel to a junction box in the crawl space where it separates into two lines, one for the dishwasher and one for the disposal. The neutral is shared, and at the service panel the breakers are separate but tied together. So if either dishwasher or disposal trips a breaker both shut off.
Just a guess here but the disposal is tripping either a shared or connected breaker.
Should be a very easy diagnosis for someone on-site.
If the house is less than a year old, it’s the builders responsibility. Maybe the disposal itself has a longer warranty BUT if so, someone has to remove it, follow warranty claim instructions and sadly have a second unit ready to install immediately. Cannot leave a non-functioning sink…
Jeff Handy
Pro Handyman, NOT A Pro Plumber
Or have misc fittings on hand to plumb the drain without a disposal for awhile.
arctic bill
Well-Known Member
I would leave it to the builder, do not do anything it could nullify the guarantee.
FishScreener
Well-Known Member
Get an air switch, and that way both don’t run at the same time.
Also: Is the drain from the dish washer going through the garbage grinder? Some, new dishwashers have built in water heating and kick it up to 160 or 180-F. (One of my sisters has one that steam sterilizes.) So the thermal switch would pop, and the casing would be too hot to touch.
Also: Is the drain from the dish washer going through the garbage grinder? Some, new dishwashers have built in water heating and kick it up to 160 or 180-F. (One of my sisters has one that steam sterilizes.) So the thermal switch would pop, and the casing would be too hot to touch.
FishScreener
Well-Known Member
Your saying that they are Installing a paired breaker, running 240 to a J-box, and then separating that into two 120s, each on a speperate leg, and sharing a common neutral? I’m pretty sure that isn’t code anywhere. At least not with NM conductors. The neutral would have to be upsized to handle the 40-amps of the two 20-amp legs, and would end up a 6-Ga. Man that is just asking for hot wire and fires.
Jeff Handy
Pro Handyman, NOT A Pro Plumber
The neutral does not need to be upsized.
It is not doing much work.
It is not doing much work.
The breakers are independent of each other. There’s a neutral and ground that’s shared.
A common use allows you to wire a kitchen with one 3wire cable and have each outlet alternate on a different circuit.
The 2 circuits are on different sides of the panel so the neutral only see the difference between the two loads.
So if one circuit was using 6 amps and one circuit is using 9 amps, the shared neutral is only seeing 3amps back to the panel.
So if one circuit was using 6 amps and one circuit is using 9 amps, the shared neutral is only seeing 3amps back to the panel.
Mitchell-DIY-Guy
Well-Known Member
Yes, @FishScreener two 120 lines, two 15A breakers tied together, three-wire (14-3 + ground) ran to a box underneath the kitchen. They separate there into two 14-2 + ground cables. From there both lines go up to a box on the wall in my kitchen. Local code here in NC dictates that the dishwasher must have a wall switch; so these two switches control the dishwasher and disposal. I’ve never been a fan of wall switches for disposals. I don’t run with scissors either…
Now, I’ve been a 20+ year fan of disposal air switches, so I added one, necessitating the wall switch to be “on” all the time. The dishwasher has digital controls and after once accidentally turning it off mid-cycle when we first moved in (the dishwasher really doesn’t like that!) I decided that switch too, needs to be on all the time. So guards were added. “Helpful” guests don’t reach for those trying to switch on lights any longer.
Now, I’ve been a 20+ year fan of disposal air switches, so I added one, necessitating the wall switch to be “on” all the time. The dishwasher has digital controls and after once accidentally turning it off mid-cycle when we first moved in (the dishwasher really doesn’t like that!) I decided that switch too, needs to be on all the time. So guards were added. “Helpful” guests don’t reach for those trying to switch on lights any longer.
Attachments
Yes, @FishScreener two 120 lines, two 15A breakers tied together, three-wire (14-3 + ground) ran to a box underneath the kitchen. They separate there into two 14-2 + ground cables. From there both lines go up to a box on the wall in my kitchen. Local code here in NC dictates that the dishwasher must have a wall switch; so these two switches control the dishwasher and disposal. I’ve never been a fan of wall switches for disposals. I don’t run with scissors either…
Now, I’ve been a 20+ year fan of disposal air switches, so I added one, necessitating the wall switch to be “on” all the time. The dishwasher has digital controls and after once accidentally turning it off mid-cycle when we first moved in (the dishwasher really doesn’t like that!) I decided that switch too, needs to be on all the time. So guards were added. “Helpful” guests don’t reach for those trying to switch on lights any longer.
So if your power blinks the dishwasher doesn’t resume the cycle ?
I wouldn’t like that......
Mitchell-DIY-Guy
Well-Known Member
Have not tried a “quick blink” as it were.
I’ve had homes with dishwashers in a number of states since I was a kid in the ‘60s. In no location anywhere except this latest house was there a power switch on the wall for a hard-wired dishwasher. Never. Soooooo…
…when people turn a switch on and off, and a light doesn’t go on and off, the immediate reaction is to do it again. And again…
…and the dishwasher doesn’t like that.
New homes just have a hot plug under the sink for the dishwasher is how it’s being done here. Disposals have a switched outlet under the sink.
Mitchell-DIY-Guy
Well-Known Member
Smart. Not here unfortunately. Had to add the outlet for the air switch for disposal. Left hardwired dishwasher as is. 
