Ten years ago, this house by renovated by a previous owner. The range hood was made by GE, although the blower was made by Best. According to GE, it typically moves 390 cfm at max power.

We bought the house 3 years ago. Until recently, the range hood seemed to do a good job. Now, it barely moves air even at the highest setting.

I checked the dampers just above the blower and the damper to the outside. Both seem to move freely. I can’t see any obstructions, although I can’t see the entire 18 inches from blower to exit.

I am getting conflicting advice of whether the fan could be worn out without other symptoms. The fan seems to make the same amount of noise as before. Some people say that things last about 10 years now; others say that if the fan motor was worn out, I would hear it. 

One suggestion was removing grease from fan blades. While it’s not clean, the grease build-up hardly seems enough to justify the collapse in function.

I plan to clean the fan blades today. But I would still like to know whether the blower motor might be worn out and how to know (without a device for testing CFM).

Lastly, I would like to hear people’s thoughts on spending $350 to replace the blower or spending $1800 to replace the entire range hood.