I guess another question is does color of the wire jacket mean anything?

Debbie, the color of the actual insulation on the wire is irrelevant when it comes to identifying what size it is. It is the outer sheathing of the wire that will help you. The sheathing is the overall covering of the group of wires.

Usually - but not always - 14AWG is white, 12 AWG is yellow, 10AWG is orange, not sure about 8AWG, and 6AWG is black.

If you look closely at the individual wires there may be markings on then to tell what size they are. Also, check the breaker to see what size it is. 40AMP will require a minimun size of 8AWG wire. If your current cooktop is 30AMP, then chances are it is 10AWG, but It *may* be 40AMP.

Oh, another thing you may be able to do to tell wire size is go to a loval electrical supply house, and buy 6 " each of 10, 8 and 6awg wires and compare them with the current wires.

"If it helps my breakers are marked 20 (2 of them)."

You have a 20A cc't according to your breakers. The new cooktop requires 40A. The cable (bundle of wires) running from the panel to your old cooktop must be #8 gauge to support the 40A. If it isn't, then you must rewire as well as re-breaker. As stated, you can't go by the color of the jacket of the cable to know its current rating. You MUST look at the number of amps printed on the cable jacket itself.

cowboy and bigbird, thanks much. I think you have answered my question. I think I knew the answer. CALL AN ELECTRICIAN. I assume the wire change can be made without holes in the walls or at least I hope so. I'm not sure how though. The basement under the kitchen, is fully finished, ceilings included (drywall).

" I assume the wire change can be made without holes in the walls or at least I hope so. I'm not sure how though. The basement under the kitchen, is fully finished, ceilings included (drywall)."

The most expensive part of this rewire will be the labor for pulling of new cable from the panel to the new cooktop. Unfortunately he will have to cut the drywall at the top and/or bottom plates of the walls downstairs. He may not have to cut the kitchen wall. If he says he'll just cut the drywall and leave it up to you to patch and fix, weigh his quoted cost with the cost of you or someone else fixing all the drywall.

Note - this is mostly a side note for anyone else who comes to this thread on a search - for the OP's situation, I agree, cutting and repairing the drywall is the way to go.

---
Not always.. there are some really impressive things an expert can do with flexible drill bits, etc. Although if you have drywall, it's usually cheaper to just cut and patch the drywall than it is to pay for someone with the skills to fish cable without cutting at the top/bottom plates, etc. (These folks usually work in old homes with plaster, historic preservation concerns, etc - if you have 19th-century handmade-in-place plaster crown molding, having someone who costs $90/hr spend an entire day fishing one wire in can still be cheaper, or more POSSIBLE, than finding a plasterer who's up to the challenge!

Thanks again, I appreciate all the info.

My home is 9 yrs old..so no lathe and plaster..thank goodness

I'm an idiot, my amp/breaker is 30 (2 for the 240), not 20 (needed my reading glasses to see it). The wire has a white jacket with black, red, white, and bare copper wires within it. I now know an update will be needed.

Thanks again for the info and help.

I see mentioned again the flexible drill bits. Can anyone give me link to gather some information? Is there really a bit that can go from a wall switch location up to the top plate??

I didn't notice this message until now, and I would hardly consider myself an electrical expert. I'm just a homeowner who did a DIY remodel of our kitchen, and learned enough about electrical work from the real experts on this forum to be able to complete the electrical work in the remodel safely and to-code.

I see that most of your questions were already answered by other posters. I would say that if your existing setup has two separate breakers for the 240V line to the current stove, its probably good that you'll be getting a electrician in, because I believe that 240V line are required to have two-pole breakers, or at least a connection between the two breakers' handles, so that if one opens, the other will too.

coovt,

I have a 4 foot long flexible drill bit that I got at Lowes. I think they also sell 4 foot long extension pieces that can be used with the drill bit. There were several times in the kitchen remodel when they were very handy.

now I am more confused than ever. Oh well, the best thing is to get the electrician.

Bob if I understand what you are saying, I am fine. It has 2 breakers that are connected...if that makes sense. If one goes off so does the other. FINE as far as the 240V, but not the 40 amps

Debbie, what are you confused about? You state above:
"I'm an idiot, my amp/breaker is 30 (2 for the 240), not 20 (needed my reading glasses to see it). The wire has a white jacket with black, red, white, and bare copper wires within it. I now know an update will be needed."

You need new wiring, 8/3, to support a 40A double pole breaker. Can't make it any simpler than that! Get yourself an electrician!