i have a 36" pro grand, and this is normal. as this is my first residential all gas range, it took some getting used to.
i love my range..how about you?

We got the ProHarmony. It's great. The cooking and baking have been fabulous. I've just never had a range make a fan noise while baking...and after so it threw me (and my husband) off. It's as loud as our exhaust fan on low. It was a surprise. I guess people who've always had pro ranges are used to it. Maybe that's why, after my extensive hours of research on ranges, this topic never surfaced. I'm glad to hear its normal. Surprised no other brand owners weighed in though. Thanks!!

The fan for the oven blows! It's loud and stays on longer than we'd want. We leave the oven door open in hope the oven cools so the fan turns off sooner.

It would be convenient if Thermador gives the user the option to turn it off.

The fan is to cool the electronic controls. There's a risk of damage to the electronic boards if the user could manually turn the fan off so it's controlled by a thermostat (not the one inside the oven cavity) and stays on until the relevant area, internal of the appliance but external to the oven cavity, cools sufficiently to reset that thermostat. Opening the oven door will disperse the residual heat inside the baking cavity directly into the room instead of slowly radiating it through the rest of the interior space, which should reduce the fan's run time.