GE Microwave oven JVM1440BH01 vent does not draw fumes from the stove top even though motor is running and air is coming out of the top vent.

It is possible, you have removed and checked the filters, still the intake is low even without the protective filters. The system will need to be taken apart to find the opstruction, or as you said a hole in the venting mechanism.

Yes, that is what they are made for, As long as it has a vent that can be used to vent the smoke from cooking it can be mounted over the stove. Normally the bottom of the microwave should be mounted 16" to 19" above the stove top. The microwave must have a vent with a blower motor in order to be used above a stove top. Most have a thermal switch that will turn the microwave vent on once the temperature reaches a set point.

Actually, the fan in the microwave is only there to cool down the magnetron which cooks the food. It gets very hot over a period of time and the maintains constant temperature across it. Suggest you use an extractor to remove fumes.

Start the fan and check the outside vent first.I have found the weatherstrip on the exterior damper can get coated with grease and will become stuck and not allow the damper to open.

You can check and / or correct your installation with help from the installation instructions.

You can download GE owner's manuals and installation instructions here.

We're happy to help you with free advice and we'd appreciate your thoughtful rating of our answer.

the vent tube in back may not have been changed over they can be vented or ventless but you must switch the flap in back you had the answer in your question ... good job,,..lol

1. You have to have exhaust pipe to connect m/w vent and this pipe has to be free from obstruction.
2. If it already connected and good, but air come from vent bar over door, then blow motor on top of the m/w was installed in wrong position ( motor has 2 -3 position depends which way air coming out up, back or front).
3. In this case you have to remove m/w from installation and change motor position.

I’m happy to help further over the phone at https://www.6ya.com/expert/vitaliy_f406165329c75ede

The dual fan in the back is the vent / exhaust / hood fa. It will run when you turn it on, or if the stove top gets too hot.

The other fan is the magnetron cooling fan, and it will only run when you are cooking. If it is not running, your magnetron can be destroyed.

You can download GE owner's manuals and installation instructions here. That may help you a lot.

Please reply back with more details if this is not yet a FixYa...

We're happy to help you with free advice and we'd appreciate your thoughtful rating of our answer.

Did you find an answer toyour question?
My microwave smells also of petrol in the same areas.

Are you running the vent fan whenever you cook on the stove top? You should.

And you should run it on high if you're having steam problems.

Otherwise, you'll need to do something like use a small counter top fan to help circulate the air better.

Please let us know if we can help further.

We're happy to help and we appreciate your thoughtful rating of our answer.