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The code could be F3 which is a problem with the either Oven sensor and/or the Electronic Oven Control board (EOC).
There is no F30 error code on a Frigidaire range that I could find.
Please post model number if you wish to fix yourself. You'll need a mult-meter and some basic tools.
Yes, you definitely should have the unit repaired under the manufacturers warranty. If you were to even start a repair they could refuse to honor their warranty.
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