Electric oven fan

Probably the cooling fan. There is a cabinet thermostat on most ovens these days (Especially wall or underbench models) to keep the cooling fan running after the cooking has finished and oven turned off. This fan will run for a few minutes to cool down the outside of the oven so it doesn't burn / discolour the surrounding cabinet or workbench. If the fan stays on all the time, I would say that the thermostat has probably jammed in the run or on position.

All microwaves do have a "transmitter" tube called a magnetron. It has to put electrical power into microwaves. To do so it gets warm or even hot. As soon as the transmitter is to hot, it must be cooled down. Most of the time it can be cooled without a fan. But as long as the thermostat indicates it is to hot, the system will cool. Even when you switched the system off. Don't unplug the microwave when it is still hot. It could damage the magnetron.

Well of you just used it than that would be why. Heat doesn't just magically go poof

Never heard of a cooling fan in an oven.they are usually used for fan baking, which speeds up cooking.

I would suspect that the problem is caused by the external cooling fan located under the outside cooker cabinet housing, which continues to operate as the oven is cooling down if it is built in, you will have to remove it from the oven housing to access the fan

Door needs to be closed in cook mode to work. You sure you put the switch in the right way up? Also you could have a dodgy door switch as the cook/cool switch and the door switch operate as a two-way circuit.

After grilling or cooking at higher temps leave the oven light on so the cooling fan continues to run for approx 1/4 hour, or whatever setting will keep the fan running...

For TOuch Control oven:
1. Press Finish Time touch pad
2.press ^ touch pad until clock displays the required am or pm finish time.
3. Press Cook Period touch pad.
4. Adjust the cooking time as in step 2, using up and down arrow touch pads. (hours and minutes needed to cook food)
5. Press Automatic touch pad.
Press Fan touch pad to select fan speed. Red indicating light shows normal speed.
7. Turn oven thermostat to desired setting.
8. Press Keep Warm touch pad if keep warm function is required at end of cooking. 9. At end of cooking time a buzzer will sound for 1 minute and the KEEP WARM cycle will now operate until the meal is ready to be served.
10. To cancel the Automatic cycle, press Manual touch pad and turn oven thermostat off.

For Multifunction oven:
1. Set time of day.
2. Turn Function switch to Finish. 0.00 will be displayed.
3. Turn display switch + to give the required am or pm finish time. (an illuminated bar in the bottom left corner indicates when the clock display is pm).
4. Turn Function switch to Cook then turn Display switch to + till desired cooking period is displayed (hours and minutes needed to cook food)
5. Turn Function switch to Auto. The automatic programme is now ready to use.
Turn upper oven thermostat to desired setting.
If keep warm function is required, turn function switch to Cook (optional)

Happy cooking!

Could be caused by either of following;

1. Faulty thermostat.
2. Faulty thermal cut out switch. (controls power to cooling fan).
3. Faulty cooling fan (not fan inside oven).

Test thermostat by setting thermostat to low temperature like 60 oC. If oven gets much hotter then its a faulty thermostat.
To test cooling fan and thermal switch take oven out and remove top or rear panels to expose components.
When oven gets hot the cooling fan should turn on. If it doesn't then check to see if there is a mains voltage present.
If mains current exist but fan is not turnig then replace fan. If mains voltage is not present then its the thermal switch.

1. Set the oven to the required
temperature.
2. Press the g button.
3. Set the total cooking time with the +
button (see the example in the
illustration right, showing 1 hour and
30 minutes).
4. Press the h button.
5. Set the cooking finish time with the +
button (the example in the illustration
shows 12.30 hrs.).
After setting the display shows the
time of day and indicates »AUTO«.
❑ The oven cooling fan will start
immediatley.
❑ At the pre-set time, the oven will be
automatically switched ON.
❑ The settings can be corrected at any
time.
❑ When the pre-set cooking finish time
is reached, a signal sounds and the
oven is automatically switched OFF.
To turn the signal off, briefly press the
h button.
6. Turn the oven selector switch to the
0 position.
7. The »AUTO« symbol blinks.
Important: It must be switched OFF
by pressing the E button.

Also here is the manual.

https://portal.bsh-partner.com/portal(bD1kZSZjPTAwOQ==)/PORTALFRAME.HTM

Good Luck