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Pots Quit Working on New Induction Stove

Posted by mbrydges (My Page) on
Mon, Jan 28, 13 at 16:01

Hi Everyone,

I've found your posts to be extremely informative when I was doing my homework prior to purchasing my new induction stove three weeks ago. Thank you.

I tested all of my pots' bottoms with a magnet and found that most of them attracted the magnet. I've been using the pots that tested positively for a couple of weeks ago. Suddenly I have a couple of pots that when placed on an induction burner I receive a message from the burner that they are not detected. This is supposed to indicate they are not induction-compatible. The burner shuts itself off and the pot doesn't heat. How could this be? The same pots on the same burners worked for the last two weeks?

To further complicate things, now some pots work on the large flex burner, but not on the round burners that are the proper size for the pot.

I am loathe to have even fewer pots now that are functional. Can anyone help me out with some ideas as to why some of these pots suddenly don't work any more?

Thanks much.


Follow-Up Postings:

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RE: Pots Quit Working on New Induction Stove

I have no answer, other than to suggest you mention what brand/model of induction top you have. I'm sure the knowledgeable folks here will want to know.


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RE: Pots Quit Working on New Induction Stove

Thanks. It's a Samsung with a FlexCook Zone for induction cooking. The model is NE597NOPBSR.
M


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RE: Pots Quit Working on New Induction Stove

sounds like a problem with the cooktop - not the pots. You could try throwing the circuit breaker and see if that resets things - if not, time for a service call.


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RE: Pots Quit Working on New Induction Stove

Can I clarify please? Do you mean to turn off the electrical breaker in the breaker panel for our house?
Thanks,
M


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RE: Pots Quit Working on New Induction Stove

It was brought up in a recent service meeting that some induction pots have a round indentation/cutout in the center of the bottom of the pot and these are not detected well by some induction cooktops.
The trainer recommended that the best pots and pans are smooth and flat all the way across the bottom. Also recommended that the pans be with-in 1 inch +/- of the size of the burner being used.


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RE: Pots Quit Working on New Induction Stove

Thanks. I discovered the hard way that my new set of frying pans labelled as "Induction Cookware" don't work for this reason. The pots I have that stopped working are in fact completely flat...

Thanks again,
M


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RE: Pots Quit Working on New Induction Stove

Yes, I was referring to the breaker in the breaker box for your house - not sure that it will solve the problem but it might.


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RE: Pots Quit Working on New Induction Stove

Suggest not throwing the breaker for the house, but the second tier breaker for the cooktop.

kas


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RE: Pots Quit Working on New Induction Stove

As for "How could this be?", I'm trying to understand if the issue relates to the magnetic strength of the metal in these suddenly-problematic pans, or if it relates to the size of the pan in relation to hob size, or both, or to something else that I can't imagine right now.

So, which brand(s) of induction cookware are giving you problems now, and which brands aren't? Does this issue relate to pans that are somewhat less magnetic than the ones that work, or is it related to the size of the pan in relation to the hob its on? Or is it some hobs are suddenly more picky about pans than other hobs?

The idea of shutting off the circuit breaker to this stove for several minutes, then turning the breaker on again to see if that allows the stove to re-set its settings about detecting pans, is a good one.

It does seem to be a change in (and problem with) the stove, not your pots. But whether the stove's sensing problem relates to how magnetic the pans are, or to their size or weight, isn't clear. And that information may be good to know before you call Samsung.


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RE: Pots Quit Working on New Induction Stove

jakvis: "It was brought up in a recent service meeting that some induction pots have a round indentation/cutout in the center of the bottom of the pot and these are not detected well by some induction cooktops.
The trainer recommended that the best pots and pans are smooth and flat all the way across the bottom.

The trainer is ignorant of the laws of physics. Accord his or her statements the same level of credibility that you give to the last striking of a clock that strikes thirteen.

The reason why the makers of non-induction smooth-top cooktops emphasize the need for flat bottom pots is that those cooktops DO need significant direct contact area with a pot. Those cooktops work by heat conduction from cooktop to pot.

Induction technology does not transmit energy through contact between the pot and the cooking surface. Induction needs no physical contact: energy is transmitted by an alternating magnetic field, and indeed it can propagate even through a perfect vacuum. Our local star (Sol: the sun) sends us magnetic fields through 93.000,000 miles of vacuum every day.

All induction ranges and cooktops incorporate a thick glass (actually Schortt Ceran) cooking surface. Because of the thickness of the glass (Ceran) layer and its mounting tabs, the point of closest proximity of a non-flat pot is usually at least 3/8" from the induction coil (underneath the glass), usually more. The difference in separation from the induction coil between the distance from that point of closest proximity of a non-flat-bottom pot and the farthest height of the bottom of the pot above the glass/Ceran surface is rarely more than a tiny percentage of the separation of closest proximity.

We have an induction cooktop, and one of our cast iron pots has three small feet around the circumference of the bottom that hold every part of the bottom of the pot at least a quarter inch above the cooktop, more than that further from the center. That pot cooks superbly on the induction cooktop,

Next time you see that trainer, call B.S. on him or her.

"Also recommended that the pans be with-in 1 inch +/- of the size of the burner being used."

There is some merit to this -- but only some. A burner smaller than the pot still will function, but the entire bottom of the pot may not be heated evenly: you can get a hot spot over the burner. If the burner is much larger than the pot, it may not sense the pot, but usually one inch too large is just fine.

This post was edited by herring_maven on Mon, Jan 28, 13 at 21:22


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RE: Pots Quit Working on New Induction Stove

Our Thermador induction cooktop threw a hissy fit a week or two ago, along with an error code. We have no idea why. Owner's manual Troubleshooting page suggested we turn off the circuit breaker for the unit. We did, turned it back on, and it was fine after that. We don't know what caused that. It never hurts to throw the breaker switch and re-boot, because these things are like computers, IMO.

We have the AllClad tri-ply cookware. While the (exterior) bottom looks flat, they're all slightly concave with 1/16" or 1/32" clearance at dead center. They all cook fine and evenly.


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RE: Pots Quit Working on New Induction Stove

herring: you state "Induction technology does not transmit energy through contact between the pot and the cooking surface. Induction needs no physical contact: energy is transmitted by an alternating magnetic field, and indeed it can propagate even through a perfect vacuum."

My intent was not to go into the complete explaination of why the pan should be smooth and flat. There was much more discussed in our meeting.

The magnetic field is not infinite above an induction hob but is calculated to be with-in a measured height of the cooking surface. The closer the pan bottom to the magnetic field being generated, the better the transference of energy.
As you said basic physics.
But your logic seems to indicate that the magnetic field is not finite and it doesn't matter how close the ferrous material is placed to the generated magnetic field that the energy transfer should be the same. Sorry but this is not true.

Cast iron does have great magnetic energy transference for induction cooktops. Even better when it's sitting flat and as close the the magnetic field as possible.

There are many different grades of induction ready cookware and some are designed and tuned specifically for induction cooking while others state "hey we are magnetic so we can be used with induction cooktops." Kind of like a professional football player and a flag foot ball player. Both play the same game but with different results.


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RE: Pots Quit Working on New Induction Stove

"The magnetic field is not infinite above an induction hob but is calculated to be with-in a measured height of the cooking surface. "

In theory, it is infinite. In practice, not so much. Though we are not talking about radio frequencies, the theory of induction from a radio antenna to a receiver is the same. And that is over several miles, but the power received goes from kilowatts to milliwatts.

"The closer the pan bottom to the magnetic field being generated, the better the transference of energy."

Yep. The amount of energy transferred falls off as the square of the distance. Or cubed. I forget.

"But your logic seems to indicate that the magnetic field is not finite and it doesn't matter how close the ferrous material is placed to the generated magnetic field that the energy transfer should be the same. Sorry but this is not true. "

He's not really saying that. He's saying that the small distance (a few millimeters) doesn't make that much difference. This is why folks can put silicon pads under their pans and they continue to function.


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RE: Pots Quit Working on New Induction Stove

I appreciate everyone's kind efforts to help. Thank you.

I have three or four different brands of pots. A set I bought 25 years ago when I graduated from University and had gradually replaced with more expensive stainless Paderno pots were working fine until this week. The brand new frying pans labelled "Induction Pans" have no makers' mark on them and I've discarded the sticker that was on them when I bought them at a kitchen store chain that has now gone out of business. The only pots currently working consistently are a set of Paderno Induction pots the retailer gave me with the stove purchase.

I believe the most puzzling element of this is not whether the pot is sufficiently conductive or whether I've matched the pots to the hob size. Everything I was doing was working for the past couple of weeks. I believe the actual mystery is in the fact that suddenly some of these pots no longer work on the hobs I've been using them on. Last night one of the pans that used to work on all hobs,worked only on two hobs, but then suddenly the detection symbol appeared and didn't work on any of them! Is this a clear issue of stove malfunction?

Much to my dismay the electricians who wired this house before we bought it didn't do an adequate labelling job on the breaker panel. With some help from a family member today I'll try the suggestion to turn off the breaker for the stove at the panel and turn it back on.

Again, sincere thanks to everyone who is trying to help. I really appreciate it.

M


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RE: Pots Quit Working on New Induction Stove

Mbrydges, you are right about the mystery: Pans that used to work don't now, or perhaps work inconsistently. And this is likely a problem with the stove, not the pans.

What I was hoping to learn from my picky questions above is more about just what problem the stove is having here. That is, is the stove suddenly misreading the size of the pot, so it doesn't work, or is it misreading the magnetic properties of the pan, so it doesn't work. If you end up calling Samsung's customer service, it is best to know as much as you can about whatever the problem is.

Turning off that breaker for a period of several minutes, then back on, should re-set the stove's detection settings for both pan size and magnetic properties. Hopefully, this will fix the problem. If not, talk with Samsung customer service. Please let us know here how it turns out for you.


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RE: Pots Quit Working on New Induction Stove

The fact the dealer supplied cookware is correctly and continuously performing as it should pretty much rules out most theories regarding the induction circuitry.
Does your older Paderno cookware have bonded pads on the outside bottoms of the pans and do they attract a simple magnet when the magnet is placed flat
on the counter and the pot is placed on top of the magnet and then lifted up?
Is the force of magnetic attraction to the old pans much weaker than the same test with the dealer supplied cookware or about the same?
Also have a look at the early boiling water bubble patterns as your new cookware heats up an inch or two of water.
This should give a good indication of the evenness and strength of the power being applied by each differently sized burner .


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RE: Pots Quit Working on New Induction Stove

I see two possible conjectures from the conversation so far.

One, the sensors that determine by magnetic sensing that an inductive pan is present above them have changed their sensitivity, or the underlying circuit threshold has changed.

Two, some of the pans lost their magnetic susceptibility due to being over heated. This is a weaker conjecture because usually the susceptible material is either cast iron that is not going to change with heating, or a 400 series stainless steel that one probably won't get hot enough to have any effect upon. The possibility exists that some other material was used in the pan bottom sandwich that could be magnetic but not very stable with temperature.

However, overall I think I would bet on conjecture one.

laat2's suggestions are good ones.

kas


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RE: Pots Quit Working on New Induction Stove

jakvis: "The magnetic field is not infinite above an induction hob but is calculated to be with-in a measured height of the cooking surface. The closer the pan bottom to the magnetic field being generated, the better the transference of energy."

1. Yes, the magnetic field is infinite. 2. Incorrect. 3. You are correct.

1. The strength of a magnetic field drops off with the square of the distance from the source, but your refrigerator magnet creates a field that does not decrease to zero even at the farthest reaches of the universe.

2. No induction cooking appliance is designed to generate a field within a "measured" distance from the surface. The laws of physics require that there is no sharp boundary, like a state line, but rather 3. a drop-off with greater distance, a continuous weakening of the field the farther one gets from -- not the cooking surface -- the induction coil under the cooking surface.

"As you said basic physics.
But your logic seems to indicate that the magnetic field is not finite."

The magnetic field is not finite.

"and it doesn't matter how close the ferrous material is placed to the generated magnetic field that the energy transfer should be the same. Sorry but this is not true."

It does matter how close the pot is to the induction coil; the closer it is, the stronger the field. But the engineering constraints in building a cooking surface impose a minimum distance between the induction coil underneath the glass and the pot above the glass. Woks aside, very, very, very few pots have sufficient curvature or unevenness in their bottom to make much of a difference in the strength of the magnetic field across the bottom of the pot. It is as if you were flying an airplane from Paris to Newark Airport (one of the three New York City area airports). The Paris-to-Newark distance is greater than the distance from Paris to JFK (another of the three New York City area airports). But -- from a practical standpoint -- there is no difference in the distance from Paris to any of the New York City airports.

"Cast iron does have great magnetic energy transference for induction cooktops. Even better when it's sitting flat and as close the the magnetic field as possible."

Sitting flat is at best fourth or fifth -- probably lower -- on the list of criteria. We have been using an induction cooktop -- not a portable induction hob -- for more than 13 years now, and we have used it with a variety of pots, some of them cast iron. Flatness of the pan bottom is so insignificant a factor in energy transference, it does not make the cut. If anybody tells you that flat bottoms are important, you have established in one fell swoop that the speaker does not have a clue what he or she is talking about.

"There are many different grades of induction ready cookware and some are designed and tuned specifically for induction cooking while others state "hey we are magnetic so we can be used with induction cooktops." Kind of like a professional football player and a flag foot ball player. Both play the same game but with different results."

We have a large West Bend stock pot that my mother bought probably in the 1930s that works superbly on induction cooking appliances. I can all but guarantee that it was not promoted at the time of sale as "induction-ready." We have one pot made in France, a Mauviel Induc'Inox, that is incredibly responsive to induction, outperforming our cast iron pots and our Demeyere pots, and even the old West Bend stock pot. Yes, pots differ, but I think that mbrydges's problem -- her pots used to work, but no longer work as they originally did -- lies elsewhere than in the flatness of the pan bottoms.


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RE: Pots Quit Working on New Induction Stove

Wow Herring... You've turned what was supposed to be helpful hints into an intellectual b!tch slapping of anyone making suggestions.
Please forgive my ignorance. I was only trying to help based on my almost 40 years in the appliance repair industry and the last 10 years working with induction cooktops.
You make it quite clear that your superior intellect far outweighs practical experience and specific training.

Mbryges, Call for service and have them check your product. It is possible that the sensing system is not measuring the change in the magnetic field when a pot is placed on it. But please, don't let them try to convince you that it might possibly be your cookware even if they show you it working ok with a pan they bring. As noted above that is not possible.


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RE: Pots Quit Working on New Induction Stove

Photons carry the magnetic field energy of the induction hob. According to the standard model, as explained by Richard Feynman, photons take all possible paths going from one location to another. Most paths cancel out, phase-wise, with other paths, so the photon path seems to be the single one that one thinks of in optics.

More to the point, the field lines loop from one pole to the other within the induction magnetics and out through the air. As they can't (won't) bend sharply in low susceptibility Ceram and air, the curved field lines extend out of the Ceram into the air. This would be difficult to measure because the protective magnetic sensor will keep the field off without a pan.

With a suitable pan, with its high magnetic susceptibility, the field lines are mostly captured in the metal, and are more steeply bent to travel from one pole to the other by going into the pan and then out of the pan over the other pole.

In this configuration, one might technically say the field is still infinite, but in practice most of it is contained in the pan base, moving radially across the field donut at the frequency the coils are driven at. If one takes an oscilloscope probe with a loop at the end, it is possible to measure the field near the edge of a pan if the pan doesn't extend too far past the hob.

kas


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RE: Pots Quit Working on New Induction Stove

Thanks to everyone for your kind efforts to help me with my new stove. This afternoon my husband and I turned off the breaker to our stove and left it off for a half hour. When I turned it back on again I tested my burners both of the types of cookware that stopped working recently still do not work on three out of my four burners. Curiously the fourth burner (hob) detects both pot types and the pots heat. Does this point to a faulty detection system in my stove and a necessary service call from Samsung?

Thanks again.


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RE: Pots Quit Working on New Induction Stove

Yes. You need to have it repaired.


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RE: Pots Quit Working on New Induction Stove

Call Samsung and set up service


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RE: Pots Quit Working on New Induction Stove

Bringing back an old thread.. I've got 3 month old Thermador Induction Cooktop. I bought a nice set of Circulon pots from Macy's. I'd say they look good, but the quality is probably not great. It is great for the non stick aspect though. But that's not why I'm posting here. For 2 months all was well, the smaller pots would work on the smaller burners (hobs as you guys call them). The smaller pots have stopped working on the smaller hobs. They continue to work on the larger. 5 burner cooktop, 2 small, 2 larger, and one flex. It's the two smaller burners giving us trouble.
I also have two quality cast iron pans. The small pan works perfect on the two small burners. As I read this thread, everyone arguing over pots, breakers, on the magnectic field from the sun:) ..I never heard anyone say that a good cast iron pan works where the other new stainless pad that is adhered to the aluminum pan stopped working. I'm looking at this and saying it's the cheap pot. But the system is certainly within warranty so I want to make sure. I will go reset the breaker, cuz we did get the same error code that a previous poster got once before. Maybe the magnetic warp field sensor is corrupted. All fun here. Any new comments please speak up.
Thanks
Hef


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RE: Pots Quit Working on New Induction Stove

yes its not a major problem you may contact to Samsung service center and tell them about your appliance problem so they suggest you what you have to do.


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RE: Pots Quit Working on New Induction Stove

The new problem is Thermador sourced, not Samsung sourced per the message. But I also think the issue is the same as in February's feisty fan fest. I think that a change in the protective sensor's sensitivity setting is more likely than the other conjectures that were raised.

Rebooting via circuit breaker should be the first exercise. If that makes no difference then a service call is the next step. To accept that the pans lost their magnetic susceptibility is a big stretch, particularly when this apparent pan problem is reported so rarely.

Now, I could easily believe that the sensors were affected by heat conducted down through the Ceram and lost their sensitivity. This could be due to a manufacturing tolerance issue in mounting location, or defective sensor, or getting the Ceram hotter than normal due to letting a pan run out of fluid on a high setting. But once one is dealing with the unit's interior electronics, so many things could be the cause that speculation is not going to be very fruitful.

kas


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RE: Pots Quit Working on New Induction Stove

Do we really know if the sensors are adjustable? That sounds like an easy fix if they are. Cast iron never fails I would believe because of the iron content.
Resetting the breaker did nothing. I have a service call scheduled for next Tuesday. We will see.
thanks
Hef


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RE: Pots Quit Working on New Induction Stove

This thread makes me very happy that I turn a knob, light a fire under my pot and things get cooked no matter the pot. I can even pretty much understand what's going on. ;-)


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