Have you seen this long-running thread which discusses how hot you can get pans on induction hobs before overheat protections kick in?

[https://www.houzz.com/discussions/maximum-temperature-on-an-induction-cooktop-dsvw-vd~2349168 [(https://www.houzz.com/discussions/maximum-temperature-on-an-induction-cooktop-dsvw-vd~2349168)

If that thread seems too long for you -- and it did run from 21012 through last month --- you might want to skip directly down to Robert Downey's post from last July.

Beyond that, I disagree with The Cook's Kitchen about needing a "3500 watt burner if searing is important" and also with using one to preheat cast iron to screaming hot temps with a "2-3 minute preheat."

I think some induction concepts might be getting elided or not fully understood.

Well, that probably sounds a lot harsher than I meant it to. I realize that some cooks believe that searing a steak in cast iron requires totally burning off all the seasoning off the cast iron at temperatures well above the 621°F melting point of lead. :>) Most of us find 500°F or so to be as high a heat as we need for searing in cast iron pans.

But the thing is, cast iron is not " a highly conductive surface." Cast iron actually has poor thermal conductivity. That means it is terrible at heating evenly unless you give it a very considerable preheating time. What cast iron actually gives you is excellent heat retention once it has been thoroughly pre-heated. The technical term for this is "high volumetric heat capacity. " In practical terms, it means that cast iron skillets easily maintain high heat levels when you add your steak or other ingredients for searing.

While a cast iron pan does not pre-heat evenly or quickly, it is not hard to maintain the heat levels once you have fully preheated it.

Uesgrl, those points incidentally lead us to what may be shutting down your portable induction cooktop (PIC). PICs have small induction fields, often only 3½ to 5 inches in diameter. They quickly heat only a ring-like (or donut shaped) area of that size in the base of your skillet. Even the high-powered commercial PICs, such as the 3500 watt Cookteks, have fields that are only, maybe, about 6 to 7 inches in diameter. Thing is that the ring within the induction field can get excessively hot long before the rest of the pan comes close to a desirable searing temperature. From the Blog at CenturyLife.org reporting on testing of heating in various kinds of pans over smallish induction fields and gas burners, it seems the ring of heat may rise well above 500 degrees while the areas around it are 200 or 300 degrees cooler. When that ring area gets too overheated, it will trigger the protection circuit on your PIC before the rest of you pan seems hot enough for searing your ingredients.

However, once a CI pan is fully preheated, those fields and heat levels are enough to maintain searing heat levels high enough for the brief times that most of us would be searing in a CI pan at home. (See below for a suggestion on how to manage this with your current PIC.)

Over longer cooking times, of course, the smaller field still produce the smaller ring of heat in the base of your CI pan which can lead us back to the problem with high heat shut-downs when you are trying to maintain very high heat levels in your CI pan.

What you get from a 3500 watt induction burner on a fullsize cooktop or stove, is a burner with a much bigger field, often ten inches or more in diameter. With these physically larger burners, your burner heats a lot more (if not all) of the base of your pan. You do not need to run it at full or boost power to get full coverage. In otherr words, it is the physical size of the burner rather than its high maximum power that matters for this topic. Regardless of the heat level you select, a bigger burner with a bigger field will give you better preheating. It will be more even in maintaining low to very high heat all across the base.

For high heat, you still will want to preheat gradually. Because cast iron tends to heat unevenly, you want a gradual preheat, ramping up through lower heat settings. This is most likely to give you much better preheating without causing a protective overheat shutdown on the Miele or other cooktops. It's that idea of making the empty pan as hot as it possibly can be made as fast as possible that will trigger the overheat sensors to shut down.

Beyond that, blasting a cold CI pan with 3500 watts of power for "2-3 minutes" induces a lot of stress in that pan which risks cracking the pan. Especially so if your CI pan is an old Griswold or Wagner. (A search may turn up several past threads on that topic which applies to other kinds of stoves besides induction, btw.)

So, what to do to get a CI skillet fully and evenly preheated to very hot temperatures for searing with your current PIC? As long as you don't feel the need to melt lead, try putting the pan in the oven and cranking the temp up to 500°F for 20 to 30 minutes. No need to preheat the oven for this, either. Just let it bring the pan to heat. Then use the PIC burner to maintain heat while you sear. Probably 60% to 80% power will be sufficient depending on your pan and PIC.

FWIW, this procedure is recommended by the likes of SeriousEats and Cook's Illustrated for fully preheating CI for the most even preheating for searing (but not lead melting) temperatures on all kinds of stoves.

Personally, for hot summer evenings when I'd prefer to limit how hot I make my kitchen, I do the preheat outside on my gas bbq grill. Or, for those times when you only want very high heat for searing the surface of more delicate foods (say, tuna or salmon steaks), try a broiler to create a finishing crust or maybe skip cast iron for these things and try torching the surface of your food with a plumber's torch like a Benzomatic TS8000.