we have a Thermador double oven circa 1999 (SCD302TP) . it works fine, but lately, about 10 min after we use it and turn it off, it will start beeping and looks like it's trying to throw an error code, but all that part of the display says is "F-" I think when there's an error, it's supposed to say F and a number (like F3), but all I get is a dash (F-).

while beeping, I can hit end and the beeping will stop for about a minute, then it will continue. If I throw the breaker for a short period of time (like 30 seconds), it will start beeping again in about a minute or so. if I throw the breaker for a while (like 15 min) the beeping stops and it goes back to normal (not sure if that's because it resets or if the problem is a heat related one and the 15 min is enough time to make whatever is throwing the error happy.

any thoughts?
is this a heat switch related issue? a motherboard?

appreciate the thoughts . seems like the whole control board is available for $7-800 but at that point, have to wonder about just replacing the whole oven.