Bottom Oven Does not work - F64 Code on Panel

If you look under the bottom door you will see a 3/4" tall slot the entire length of the door. This is where the cooling air blows out. In the middle of this slot is the air switch enclosed in a 5" long metal housing. You can see a thin metal paddle sticking out of each side of the housing. These paddles are spring loaded to angle slightly back. When the fan is on, the airflow will push the paddles forward. If they do not move forward, then you will get the error code. The simplest solution is to vacuum out all of the normally collecting dust that keeps the paddles from moving. To better access and clean the area, the black trim piece that forms the slot can be removed by unscrewing the two retaining screws. That can be more easily accomplished by first removing the lower door. This is very simple. With the door fully open, rotate the small metal clip on each hinge so it hooks over the protrusion on the other part of the hinge. Then lift up on the door (close it part way) and slide (pull) the door and hinges out of the hinge slots. There is no need to remove the entire unit from the wall.

I found out from Thermador customer service that error code F64 means that the lower fan switch (located inside the bottom trim on the right side) is not being detected as closed. In my case, this was because the header (P4) on the Display panel had broken loose from the PC board and was no longer making contact. P4 is where the lower fan switch wires connect to the control boards (actually the display panel).

Good luck!

My bottom oven would not work and the F64 error would come on.....it was an easy fix, seems like the fan switch was stuck...the dual switch has two 3 inch paddle fan blades that were bent and could not move, thus the error F64...to fix this problem gently bend the sheet metal fan/paddles so they do not rub against the bottom frame or the upper frame. the dual switch is located at the very bottom of the front panel, you have to remove the black bottom trim with two screws.

I had this several times now - ultimately the cause was the air sensor switch which makes sure the cooling fan (not the convection fan) is running.

It turns out this switch is not sealed, is probably being overstressed for temperature, and after a while collects enough grease and dirt in it to stop working.

The upside to not being sealed is that once you remove it, you can take it apart and clean it. This is good, since the website for parts ordering doesn't clarify which of two items listed as "SWITCH" is the one I need, and after 30 minutes on hold calling their parts department, I was disconnected.

Hope this helps....

For the C302ZS/01 model, the sail switches can be accessed by pulling the oven out from the cabinet and removing the back panel (its about 2 dozen screws or so but easy to do). There are two switches, one for the upper oven which is top right and one for the bottom oven which is bottom left (as you look at the back of the appliance). Most times it just needs to be cleaned but be sure the check your connections and wires for any evidence of burning. The only place I could find the part (if you need to replace) was on ebay.

ZacPack's answer helped me but in my case wasn't enough on its own to get the paddle for the lower oven to work again. I had to remove the grill above the lower oven door and clean the dust out of the fan at the back that area that blows the air down to the paddle slot. That improved the airflow to the point where the paddle would work again and the error doesn't pop up.

I have the same problem and im in oakhurst. the repair person thought it was because the bottom oven does not close fully which i should have had fixed under warranty. they are coming oout on friday