Thank for the work and hard earned solution, Detective keitel.

Where is my utility knife?

You done venting now? (Sorry, couldn't pass that one up.)

Seriously, you've helped quite a few here with your findings

keitel:
Thank you for the info on the vent-a-hood damper. After I read your post, DH checked and our damper only opened about an inch. He took everything apart, and then I heard strange sounds coming from the kitchen (I was afraid to check).

He cut a little off the 'metal flange' and re-bent the flaps further so the plastic dampers can open all the way.
BIG difference in venting! Also, it seems to be a little quieter.
Thanks for persevering!

Yeah, I suppose adjusting the metal flange would affect the same change. We decided to cut the dampers just because the rep and I decided that they seemed easier to replace if something went wrong. Glad it helped, and I agree, it makes it much quieter given that the air has free flow now.

I'm so glad you posted this. Our VAH (1200 cfm) was installed last Sept. and the blowers on the left side only had one speed. I showed this to DH last night, he checked and, yep, that was the problem.

He bent a couple of tabs and the unit is working better, and MUCH quieter. He did mention that the clearances are very close, so not unexpected that this could be an issue.

Thank you, Thank you, Thank you!!!

I'm glad to hear that the information helped you. Ah, the beauty of Garden Web.

The flaps on my VAH are aluminum, and I have the opposite problem, the flaps don't fall down. I noticed it the last time I cleaned it. They are not hung up on the sides, I think where they bent the metal, to for a hinge is too tight, or it's filled up with grease, and gunk. I sprayed WD40, but it didn't help, finally gave up, and put it back together.

bob411, if there's a grease accumulation, I've found that WD40 is usually not the solution. WD40 is a light lubricant mixed with a penetrating solvent and it will temporarily free up binding mechanisms with old grease on them, but after a while much of the solvent evaporates and the old grease thickens again, causing the original problem to reappear. The proper solution is to wash ALL the old grease out with a solvent and then apply the correct type of fresh lubricant, if any. Exhaust vent louvers and flaps should work with no lubricant at all. Paint thinner works well for removing petroleum grease from most metals; you may need to use a small natural fiber brush, such as a disposable acid brush, to accelerate the action of the solvent. Accumulated rancid cooking grease can be removed with liberal application of Simple Green and/or household ammonia, full strength, followed by a water rinse.