Delonghi dfs090 electric fan oven, knob does not seem to be operating oven correctly however it seems to be intermittent, sometimes when turning knob the oven does not switch neither internal light not fan nor oven, however when it did last night it switched on and operated fine and then oven cut off completely, what is the possible problem and can it be fixed.

Possibly the fan in the oven has developed a fault. Get an electrician to come and test the fan.

The worker should do tests on the oven to make sure everything is safe to use once any repairs are done.

ISOLATE MAINS BEFORE REMOVING ANY PANEL
Without going into the issue too deeply it sound like you have one of two possible problems.
The first would be a visual inspection, not worked on this type so I will generlise the solution, check element or elements on oven, fan assisted usually have the element in front of the fan, you may have to remove the fan to remove the heating element, checking power, a multimeter would be require and extreme caution as mains would have to be restored to the appliance while panels rear were removed.
Check on meter A/C above 250 volts range if not auto ranging meter, two terminals on heating element should read 230 volt A/C, if no voltage, the problem can be in several areas, check this first. Then send me the details, if mains voltage is detected then it is safe to presume the element is faulty.
AH also before the above look at the element if you have a Black Grey spot or blow out just replace the element. Elements are quite easy to obtain for most ovens a local electrical supplier or whitegood.co.uk
you will need the model and serial number of the appliance.
Hope this is helpful
john

The setting with the fan is fan only function.
The setting with the fan and circle is for fan and element for heating the oven.
Please rate my solution.
Thankyou.

F2 Oven temp exceeds 590 w/ unlocked door High resistance or interference in oven temperature sensor. Replace oven temperature sensor F2
Note: Also see fan thermal switches Indicates that oven is over temperature in one of the following modes within either a cooking or clean mode of operation.
· Control senses oven temperature above 650 degrees F with the door circuit in the unlock mode.
· Control senses oven temperature above 935 degrees F with the door in the locked mode.
· Stalled cooling fan or airflow problem. · Look for welded relay contacts. (Heating elements on in off mode).
· Look for open thermal switch in lock motor circuit. Switch is normally closed and will open if area overheats due to fan not operating. Look for cause - fan thermal switch not closing, fan stalled, etc.
· Look for high resistance in the oven temperature sensor circuit due to high contact resistance (poor terminal crimp, deformed terminals, loose connection) or intermittent solder joint on control or intermittent oven temperature sensor.
· Look for electrical noise interference in the oven temperature sensor circuit (Ham radio, cordless phone, etc.).

sound like fuction switch has blown apart quite common and the noise is prob coming from cooling fan and not the main one inside.

seems the heating element burnt out, inspect it for small melted section, element needs replacing, about 25$ at hardware store

You can request a manual from the manufacturer or you can get one online in Delonghi website by quoting the model and serial # of the product.

We just moved in to a place that has this oven, if you use the setting with the fan with a circle round it, seems to get hot! Don't know what the other is for though!

Hope it helps!

Pete

I had the very same problem. I slid the oven out of the wall about 6" or so, unplugged it, plugged it back in. It worked. I'm not sure if I jostled some connection, or if unplugging/repluging it in reset some sort of circuit fault.

It is probably and electrical service issue. If this is a North American unit, it uses two electrical circuits to provide power. You must find and reset the breakers and check that the wiring is operating as intended. Less likely: It could also be a manufacturing defect. DeLonghi uses screw compression connections on some products. Sometimes, they don't work well.