Bosch Extractor Hood help

[diamondpack]

Bosch extractor hood model number DHE635BGB fitted in our kitchen about ten years ago. Normally whenever filters clogged up, need replacement then extractor used to be become less efficient. When we change filters used to restore the efficiency back and you can really noticed the steam coming out from outer end of square ducting.
We had good size combination of square and round pipes used in ducting kit, never had problem at ducting side of the system. Lately we noticed that extractor motor is running but steam is not going out. I already replaced filters but no improvement.
I just need advice from any member who comes across with identical problem and what was the solution. I suspect might it need inside cleaning by removing outside grill or might be mechanical moving part stop moving due to any belt broken etc. You guide help will be appreciated.

 

[Burnerman]

You'll only see steam when its cold outside (i.e now) - is the extractor actually pulling the fumes away?
Try running it temporarily without the filter in.
They do get grotted up inside, but usually not enough to impair the performance if the filters are clean.
Put your hand over the outside grille - can you feel air being pushed out?
John

 

[diamondpack]

You'll only see steam when its cold outside (i.e now) - is the extractor actually pulling the fumes away?
Try running it temporarily without the filter in.
They do get grotted up inside, but usually not enough to impair the performance if the filters are clean.
Put your hand over the outside grille - can you feel air being pushed out?
John

I removed the filter grill, if I put my hands close to motor I do not feel that motor is pulling fume. It used to very obvious and noticeable air pull even with filter grill in placed prior to this problem. I checked that all pipes in ducting are intact. However I did not go outside to put hand in front of outlet end of ducting. I suspect will not make any difference; however will check today if I feel difference then will let you know again. Any other aspect which you may suggest can cause problem? Many Thanks for your input