I can not control the oven temperature. When I turn on the oven the temperature keeps increase the food will burned.

My suggestion is NEVER EVER use the self cleaning feature. We see questions like yours at least 4 times a week. Locked doors, burned out elements, burnt out fans and even frazzled control boards. The temperature is just too hostile.

The oven is cleaned by heat, at temperatures above normal cooking temperatures. During the cleaning cycle the oven is heated to about 880 degrees Fahrenheit (471° C.). At this temperature, food soils inside the oven decompose, leaving behind a small amount of ash.

There are a few ideas here

https://www.justanswer.com/uk-appliance/65fdd-ra-ce.html

But Neff says you need a Service Call.

https://www.neff-home.com/uk/service/support/ovens/error-codes

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How to change lower element in DeLonghi Airstream Convectio Oven??

Preheat ovens only when necessary. With conventional ovens, keep the preheating time to a minimum. Unless you're baking breads or pastries, you may not need to preheat the oven at all.

Food cooks more quickly and efficiently in ovens when air can circulate freely. Don't lay foils on racks. If possible, stagger pans on upper and lower racks to improve air flow.

Use glass or ceramic pans in ovens. You can turn down the temperature about 25°F and cook foods just as quickly.

Do not open the oven door often to preview the food. Each time you open the door the oven temperature drops by 25°F. Watch the clock or use a timer instead.

Full-size ovens are not very efficient for cooking small- to medium-sized meals, it generally pays to use toaster ovens or microwave ovens.

Check to be sure the oven door gasket is tight. Adjust or replace gaskets as required.

If you have a self-cleaning oven, consider using the self-cleaning feature immediately after regular baking when the oven is still hot. Less energy will be required to reach the cleaning temperature. Try not to use the self-cleaning feature too often.

Keep range-top burners and reflectors clean; they will reflect the heat better and save energy.

Match the size of the pan to the heating element; more heat will get to the pan and less will be lost to the surrounding air. A 6-inch pan on a 8-inch burner will waste over 40% of the energy.

On electric stove-tops, use only flat-bottomed pans that make full contact with the element. A warped or rounded pan will waste most of the heat.

When cooking with a gas range-top burner, use moderate flame settings to conserve gas. Also make sure the pilot light is burning efficiently, with a blue flame. A yellowish flame indicates an adjustment is needed because the gas is burning inefficiently.

Whenever possible, use a pressure cooker. By cooking food at a higher temperature and pressure, cooking time is reduced dramatically and energy use is cut by 50-75%.

It would not be element bc it only works when supplied voltage. And obviously it works when supplied voltage. Whatever is sending voltage to the top element that shouldn't be is the issue. Such as control board

Hi,

Ok, I need some information from your to answer this question correctly. 1. How long is your preheat time? Must allow 30 mins for the oven to heat and settle, failure to do this you will have temperature issues, usually burning food. This unit was designed to use both elements to preheat, so inserting food too early will burn your food. 2. What rack position did you select for the product you cooked? This is really important!!! I am a certified tech and I understand this issue you have, but information is key to answer this for you. Most people don't read the instruction manual and treat this oven as all the others on the market. As the ovens get more features, its important to learn how to operate as instructed to avoid these issue and have a great turn out of good food at the same time. Please get back to me if you would like more help. Thanks Gere

I’m happy to help further over the phone at https://www.6ya.com/expert/gere_bf68e6055dd61249

What is the model number of your unit?

replace the thermostat------It controls temp. rise and fall

Usually this is due to a bad temperature sensor. Sometimes it's due to a control board malfunction.

If you can get an accurate measurement of the oven temperature (which is not as easy as it sounds) you can do some diagnosis from the outside:

You need an accurate thermometer or thermocouple into a DVM. Make sure there are no obstructions in the oven (baking sheets, etc). Make sure you are measuring the temperature in the center of the oven cavity.

1. If the average measured oven temperature agrees with the display, the sensor is probably ok. The controller cycles the element on and off, at a rate that results in a correct average temperature. So you have to record the thermometer reading min and max over several cycles.

2. If the sensor seems ok from #1, it can be verified by disconnecting it and measuring its resistance. Should be 1080 ohms at 70F.

3. If the sensor seems ok, but the oven temperature is erratic, then it's probably a control board issue. We repair these at www.fixyourboard.com

HI. the oven temp sensor is malfunctioning. have it inspected for damage. check the wires leading from the control to the sensor for cuts and damage as well. replace the sensor if these issues with heating persist.

When foods are burned, soggy, or baked unevenly, it generally means heat isn't being distributed evenly throughout the oven, its escaping out the door or the controls are out of adjustment. 1) Remove any aluminum foil from racks or the bottom of the oven. 2) Check the door gasket and, if necessary, have it replaced. 3) Be sure nothing is obstructing the vent. 4) Reposition the oven racks so baking pans aren't too close to the heat sources. 5) Check your baking pans. If they're dark, they may be burning your food. Reduce temperature by 25 degrees F when baking in dark metal or glass pans. 6) Recalibrate the controls.