Why is my combi oven fan on long after cooking?

Question

My Whirlpool combined oven has a cooling fan that is on while heating. But when the time is up, it often remains on for several minutes after that.

We noticed the following:

• While oven cooking, the fan remains on for around 5-6 minutes, then it turns itself off. Sometimes it turns on again after a couple minutes, then off again for good.
• When in microwave mode, the fan does turn off when opening the door. But over a certain threshold of time/power (ca. 2 minutes at 900W) the fan stays on for 8-10 minutes before turning itself off.
• For the first X minutes nothing can stop the fan, except unplugging it off mains. No knob rotations, no button presses, no door open/close. Between X and Y minutes the fan with can be turned off with the stop button. After Y minutes it shuts itself off.

The oven is less than 2m far from the dining table and the fan noise is quite annoying. We're tempted to unplug it when we're ready to eat, but I'm worried it may get damaged.

Why is this post-cooking cooling necessary? Is it to protect the oven itself from overheating? Nothing stops me to finish a 90-minute cooking at 250°C and immediately start another one, so the oven wouldn't have time to cool off anyway. Even more so when microwaving, since it only heats the food and not the oven itself.

Is it a fault or is it done by design? If the latter, does it have a name? Can't find anything on the manual. Do other ovens have the same behavior?

Answer 1

As this is a cooling fan, and not a fan to circulate air within the cavity, it probably does need to stay on for most of that time after a long cook, for 2 slightly different reasons.

• In microwave mode the electronics heat themselves up, and some components can get pretty hot.
• In oven mode the heat from the oven warms the electronics. This heat can keep working its way out of the cavity for some time.

It's possible the manufacturer has built in a worst-case assumption combined with a timer, in which case it's likely to be running for longer than necessary. They may alternatively have used a thermal switch. In this case improving airflow through the cooling vents will help - ensure you at least meet the requirements in the manual, and don't place stuff on top.

The turning back on again after oven mode suggests a thermal switch, at least in this mode. If it's built-in you might need to look further at the ventilation, and maybe vacuum some vents.