My concern about these specialized appliances is that if the unit fails, then you have to replace the entire countertop as well. This may not be a dissuading factor, but I think of the several people who had those GE Wall-mounted fridges where I grew up (there must have been a good salesman in the late 1950s) another specialized appliance, in a time when they were usually long lasting and reliable, and they had all more or less failed and none of the kitchens had been designed to fit a refrigerator anywhere else.

"...when my husband does use it, there’s a pretty good chance he’ll forget to use the “Invisamats” they tell you to use." This would worry me, as it says right on their website, in all caps:

Yep, those are exactly the points that concern me, and why I’m asking for experiences from people who have used an Invisacook cooktop for a while. Re the mats: because of the husband factor I wouldn’t even have considered the Invisacook, but in some of their own videos, it sure looks like they’re using it without the mats.

I agree with others who are dissuading you from purchasing a specialty appliance that if it fails or you don't like it, will require ripping up your counter at great expense.

" but in some of their own videos, it sure looks like they’re using it without the mats " I noticed that too! I thought it was misleading, but it's worth calling the supplier and asking because they specifically say porcelain and granite counters. Does that mean you can use it without a mat on other types of counters (like quartz or quartzite)? (Doesn't seem right, but I watched the video too and was surprised to see the use without the mats.)

My island is 8.5 x 4, how much is the porcelain stone that size?

I want to get invisacook as well

@palimpsestThat's not correct. If the unit fails and can not be repaired.... you just replace the unit. There is absolutely no requirement to replace the counters.

Invisicook's website says:

Is there anything special I need to do with my induction cookware for it to be used on my countertop?

Nothing need to be done to your cookware, but we provide you an InvisaMat for each burner for the following reasons:

1. Prevent pans hitting your countertop.
2. Prevent scratches from blemishing your countertop.
3. Keep the metal from your pan from touching your countertop, helping countertop stay cooler longer.

Further, in their download about natural stone disclosures, it states:

STAINING: Discoloration of the marble or granite, whether general or localized, is staining. Staining may be the result of exposure to a variety of exterior substances, or to internal occlusions in the stone or structural elements.

Some of the most common types of staining and the causative agents are:

1. Oil / grease stains

2. Dyes and inks

3. Organic stains: Organic stains are caused by direct contact with decomposing

organic matter, such as leaves, flowers, tea, or coffee.

4. Metallic stains: Two major categories of metallic staining are based on either iron

or copper.

5. General dirt, soot and pollution

6. Surface Temperatures that can reach over 300 degrees, not through the use of an approved heat resistant Mat, APPROVED by Invisacook Inc, AND NOT used for cooking anything above this temperature, is excluded from the Warranty of the Invisacook product.

In the download about InvisiMat it explains its purpose:

It also states there that it reduces sliding and acts as a layer of protection for your cooktop.

Conclusion, you'll void the warranty and likely discolor your countertop.

@chicagoans, it specifically states in the manual that it is designed only for all 12mm porcelain, some 20mm porcelain, or 15mm granite. Quartz or quartzite would not be recommended and void warranty ... not to mention that the resin in the quartz would do rather poorly with the heat - scorching, deforming, you name it.

ljohnson04 I think the point people are making is that if the unit fails you are forced to replace it with the same thing (which you may end up not liking very much) or else you will have to rip out the counter to install a conventional cooktop. Perhaps you could salvage your counter, but likely not, and it'd be very expensive.

If the undercut zone of the Invisicook is not larger than the cut-out needed for any of the larger induction cooktops, such as the 36-inch Electrolux/Kenmore/Frigidaire, then cutting a hole of the appropriate size can be all that is needed. Obviously the choice of 30 or 36-inch replacement cooktop, as well as allowable cooktop chassis depth, will depend on what cabinet support layout is under the counter.

@HU-918119203 Any fabricator with even a modicum of skill could cutout an opening for a traditional cooktop no problem.

You can also put the little cork feet on your pans instead or youncan use a large silicone mat rather than the individual burner ones i too am most likely getting the invisi cook in a month or two with porcelain coutnertops if the unit fails, you wont have to get new countertops … just cut out a space for a stove top if you dont replace with invisacook

OP here. For anyone else considering an Invisacook: I found a showroom that has one installed, and tried it. I picked a pot and a measured amount of cold water and timed how long it took to boil on my current Thermador induction cooktop at the “Power Boil” setting. It was just short of two minutes. Then I took that same pot to the showroom, filled it with the same amount of cold water, and turned the Invisacook on to the highest setting. At two minutes, the water was only slightly warmer than the tap temperature. At four minutes, the water was warm, but nowhere near boiling—I could still comfortably put my finger in it. Since speed matters to me, at that point it was clear an Invisacook wasn’t going to work for me, so I didn’t bother to keep timing it. But as always, YMMV. If speed doesn’t matter as much to you, it might work you.

@Susan Lewis So helpful, thanks for posting!

I had one of the original 3 burner Invisacook units.I do also have another traditional induction cooktop, so I thought this would be an auxillary unit. I use the Invisacook more frequently then the traditional cooktop. IThe original Invisacook could not bring a pasta pot of water to a boil, although 2 cups of water came to a boil in about 3 minutes. One of the burners did fail and a replacement was sent under warranty. You DO NOT need to rip out your contertop to replace the unit. I was able to loosen the clips and rails that were used to install it. I just slide the new unit in place and retightened everything. The replacement unit had been updated it and now has more power. It takes about 20 minutes to bring a full pasta pot of water to a boil which is fine with me most of the time, because I'm prepping other ingredients. If I need to boil it faster I can use my other induction cooktop. I do love my invisacook and use it quite a bit of the time. It is under a porcelain countertop in my Island. I like my new Invisacook even better than the original. The burners are a bit different and and there is more power which is a huge improvement. The main reason I chose to go with an invisa cook is that I'm a seamstress and needed a completly flat and large kitchen Island to put cutting mats on to cut out fabrica. I also love to entertain, and having a cooktop in my Island means I can face guests while I cook. My other cooktop, my back is to the guesta and I'm facing a wall. There is also the "cool" factor when people see you cooking on it.

@Susan Lewis, thanks for posting the speed test. I was surprised at how thick a counter Invisacook "works" with (12-20 mm!), since as with most things physics, power decreases by the square of the distance (Intensity = 1/r^2). Your speed test confirms it!

@sarahsew Thanks for posting your experience, it's very helpful. While speed is currently the big selling point of induction (20 minutes is an improvement?!?), invisibility is a whole other selling point you can't get with any other technology! Also, IIRC water boiling tests show 9 min for induction, 11 min for 25,000 BTU NG, but all that depends on your elevation, surface area of the pot, and amount of water, so TBH 20 min may or may not be terrible.

I'm thinking of getting two 2-burner Invisacook units (because 120V) to use under a porcelain dining table for Chinese hot pot, which our family does 2-3 times a month. I'm hoping thinner table surface = faster cooking. I also think this would be great to keep pots of food warm throughout your dinner rather than room temp by the end of the meal. Though I'm the only one in my family that cares whether the food is hot, so maybe I'll just eat on an induction compatible plate, LOL

"I was surprised at how thick a counter Invisacook "works" with (12-20 mm!), since as with most things physics, power decreases by the square of the distance (Intensity = 1/r^2)."

Power (irradiance or flux density) only decreases as 1/r^2 in the 'far field' (many times the source physical size). In the near field, other geometrical factors apply. The 'far field' of a flashlight, for example, is roughly equal to the diameter of the beam at the flashlight divided by the beam width in radians. Note that for a flashlight the wavelength of the light emitted is minuscule compared with the beam size.

Induction uses frequencies with wavelengths vastly larger than the coil size, so energy propagation in an antenna or light emitter sense is not relevant. Instead, the power above the coil is only virtual until an appropriately susceptible material capable of inductive coupling and resistive heating is placed into the field. To first order, the portion of the toroidal field that intersects the pan base would represent the fraction of power transfer, but the pan base also reacts with the field so the actual field line intersection is complex.

The toroidal field may be though of as a donut with an outside diameter equal to the coil outside diameter, a donut hole diameter equal to the coil inner diameter, and a sectional half diameter equal to the difference between coil OD and ID. With a pan displaced above the coil, some lines will in principle pass under the pan and not contribute to heating.

This is difficult to test in the limit because modern induction cooktops sense presence of inductive material above the coils and shut off power when an insufficient amount is detected.

Thanks for clarifying, @kaseki. So not quite as simple as I thought.

For my application of placing under a porcelain dining table for hot pot use (mainly maintaining heat or a simmer-type boil) rather than as our main stove, it might just do the trick, though sometimes when you add broth, it may need to bring water to a boil, though we could preheat the broth before bringing it to the table.

I think a derivative of my comment is that the larger the diameter of the coil, the larger the gap can be for a given fractional loss in power transfer.

While I have observed that a hot pad on top of the Ceran still allows bringing water to a boil on my smallest hob (I think demonstrated with my original Kenmore, not present similar Frigidaire), I haven't measured this, so maybe I'll remember to do so when I next boil some eggs.

My standard water/egg load in an ancient Revereware drawn stainless steel pot takes almost exactly 2 minutes on 0.040 (1mm) silicone pads (plus Ceran thickness plus coil insulation thickness under the Ceran). The kitchen hot pad I intend to use is 1/4 inch (6mm) thick.

@D Ahn: "I'm thinking of getting two 2-burner Invisacook units (because 120V) to use under a porcelain dining table for Chinese hot pot, which our family does 2-3 times a month."

Is it worth the effort and expense to build an induction element into a table that you use so infrequently? This TILLREDA Portable induction cooktop* is only $60 and you could put a grommet (https://www.amazon.com/dp/B076F2JNTG) in the table top (of any material) through which you could drop the cooktop cable.

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*https://www.ikea.com/us/en/p/tillreda-portable-induction-cooktop-1-zone-white-10493520/

@wdccruise thanks for the suggestions, that's similar to what we're doing now. But 2-3 times a month seems pretty frequent to me when I'm pulling the portable hobs out, plugging it into extension cords, moving the pots from the stove to the table, moving the pots back to the sink, wiping down the induction hobs, moving it back in the cabinet… and the entire setup is ugly and clunky. I'd like a sleek invisible setup as described above, BUT still just mulling the idea over for now.

Hot pad results: With one 1/4-inch hot pad, time to boil on 'power boost' (2000W) went from 2 minutes to 2 minutes 20 seconds. Power settings to maintain gentle boiling was 7 to 6.5, rather than 6 to 5.5 with the silicone pads.

With two 1/4-inch hot pads, time to boil went to 5 min 30 seconds. I didn't bother cooking the eggs with the pads present.

Note: Flat part of pot base is 5 inches diameter, coil is nominally 6 inches in diameter. No effort was made to assure that the eggs were identical in size (nominally large, initial temperature 38F), or that the water quantities were exactly the same. Other pan base materials and thicknesses may result in different times.

Observation: One quarter-inch of added pan spacing is tolerable for utilization, but a half-inch degrades performance too much.

Conclusion: Removing the Ceran and putting the coils under 1/2-inch of granite or porcelain would yield a slightly wimpy induction cooktop; with 3/4 inch of granite performance would be too poor for my usage. Additional power and cooling could potentially somewhat compensate.

Common sense would suggest that if the unit fails, you can easily unclip and remove it, then either replace it with a new one or cut out the space it occupied and install whatever you prefer.🤦🏽‍♀️

How much does this cost?

what is the pricing of this? i need more counterspace badly, but i'm also not trying to go broke.

"As seen on Southbay Green Design’s website, the 1-burner Invisacook has a trade price of $975 and a retail price of $1100.

"As you add more burners, the difference between the trade and retail price gets higher too.

"For example, a 2 burner Invisacook costs $1550 in trade price but $1700 once in retail. That’s a $150 increase compared to the $125 difference on the 1-burner Invisacook.

"The Invisacook 4 burner cost jumps within the $2700-$3000 range. Meanwhile, the Invisacook 5 burner price has a trade price of $3100 but goes on retail for $3400. Both have a $300 increase once you buy them from a retailer." - Invisacook Pros and Cons

thank you for this! :)

@sarahsew Would you mind sharing a bit more detail. What brand / thickness of porcelain did you use and how happy are you with it? And, how many burners did you get? Thank you!

I have Decton porcelain. It is the 12mm thickness. One of my posts talked about bring water to a boil. I have switched pots and my pasta water comes to a boil much faster. The original one was an induction ready disk in just the bottom of the pot. The newer pan is a fully clad pan. I still love the Invisacook,

@sarahsew - thank you

i only see comments about boiling. what about frying?

We had Invisacook in our home build plan, but when our general contractor went to price our Dekton countertops, the installer recommended not using it. His two concerns where that Dekton tends to chip easily at sharp corners and he's had homeowners complain about discoloration from using Invisacook with it. (I know the installer needs to apply a chamfer to sharp edges, but assume he knows that too).

Has anyone here come across these two issues?

Both of mine are installed under granite and I’ve never had any issues with them.

Thank you, Marie K, for the extremely extensive and experienced answer! From a prospective Invisacook buyer

@Marie K - Thank you! I've been following and reading up on Invisacook for a while now and this is the first time I've seen such great detail about how the specific cookware makes all the difference - which makes sense. I even saw a demo in San Jose at a fabricator and was bummed at how long it took to get a tiny amount of water boiling. The demonstrator knew a lot about porcelain slab but less about the cooktop and said nothing of the cookware. If you are anywhere near the San Francisco Bay area and willing to share who you worked with or have videos to share, I'd be so grateful!

@Linda I am 2 hours south of San Francisco., in the Santa Cruz mountains. I had the unit installed by a place out of Monterey who both had granite and porcelain and also had installed these units prior. I'm not sure how far North they work:

.https://www.clfrost.com/

They did a great job. They were the ones that helped me do the granite test. I think if I had time remaining (we were trying to make Christmas), they would have allowed me to test another few pieces of granite, which I would have done and even paid them to do. I did not pay for the piece of granite that did not work out.

I had looked into other places, but at the time (1.5 years ago) none had experience with installing the burner units themselves, only countertops. I wanted a single contractor for both counter and the unit so that I knew that my contractor knew everything that was needed and would not make a costly mistake.

I hope this helps!

And regarding videos, I have been considering putting a video up on Youtube since none address everything. I will update if I do that, as a service to those who are looking.

Thank you!

@Marie K - thank you so much for your detailed report on Invisacook pros/cons. We are remodeling this year and seriously consider installing Invisacook to gain as much continuous countertop space in galley configuration. Will be going to showroom Bedrosians in San Jose to check it out.

@Sayler Inc. - call Bedrosians in San Jose before you go. I called way back when (over a year ago) and at that time, they had no clue what I was talking about. I ended up going to @Marblus Granite and Tile, Inc. instead. The lady there was very knowledgeable, including about fabrication for porcelain sintered stone counters --and gave me an Invisacook demo.

@Linda, yes you are so right! I was totally unimpressed with Bedrosian showroom, first I guess I was not taken seriously and I knew more about Invisacook than the demo guy. Then he left to answer ”an important phone call” and never came back to finish discussions. OK none of the staff were helpful nor have courtesy in sales ethics. Good riddance.

Like you I yelped Marblus and it was the best trip. Sales person was up to date on Invisacook and was able to professionally discuss everything including historical evolution of this technolgy that started years ago from Europe to finally here in USA. Because Marblus was in renovation stage of the showroom I’ll have to do a return trip to look at countertop options