Fan making loud noise

Try some "Loctite"

This video shows how to test and replace the faulty heater element on the fan oven on a Hotpoint double oven.

There is a cooling fan for upper and lower oven they run at the same time no matter which oven in use it is fed from the oven manager no way to trouble shoot without pulling oven out some models use same fan for both so you could have a blower on hand remove back panels to access fans take a lead off fan to determine which one noisey

It sounds like the fan itself is bad. they can get loose and start to rattle or rub against the frame.

From what you describe is happening, I would say that it is the fan that is causing the noise, not neccesserily the oven fan, because there is an external cooling fan as well, and these are the only moving parts that could cause a noise.
Hope this helps.

It will be the external cooling fan that is causing the noise.
Probably worn beaqring or broken fan blade.
Normally, the only solution is to replace the fan motor.
It is located at the top of the oven, usually at the rear, but not in every case.
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Thankyou.

JUST REPLACED BOTH FAN MOTORS ON A DOUBLE BOSCH 755. DIDNT HELP MUCH.THE FAN IS LOUD COMPARED TO OTHER BRANDS.UNLESS YOU NOTICE A DRASTIC CHANGE IN NOISE, DONT WASTE YOUR MONEY ON A NEW FAN MOTOR.ITS JUST THE WAY IT WAS MADE.

The fans are not normally repairable, but there is no problem obtaining replacements.
On a double oven, there are usually 2 fans fitted.
There is an external cooling fan usually fitted on the top of the oven, you would have to remove the top cover of oven to access it, and possibly the rear panel as well.
Then there is the fan fitted in the main oven compartment.
If you open the oven door as it is working, you should be able to determine if it is the fan oven or the external cooling fan that is the cause of the problem.
If you determine it is the fan in the oven that is noisy, then to undo the fan blade assy, you have unscrew the nut clockwise to remove it. as opposed to the normal way of undoing a nut.
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Thanks.

You are probably trying to undo the nut the wrong way.
It is a left hand thread, so to undo it, you go clockwise, as though you were trying to tighten it, and vice versa to tighten it up again. If you can't unscrew the nut, you will have to grip the fan spindle with something whilst you undo the nut.
Plz rate my solution.
Thanks.

what you are describing is the cooling fan. That fan will come on to keep the electronic control panel cool. It is normal for tat to come on even if your done with the oven. I dont think is should be as loud as you describe. I would try the oven again and if it is still loud I would call for service because it is new. That fan will also come on when you use the self clean cycle.