Range Hood Rattles or Shakes While It Runs

What it
usually means.

A blower spins thousands of times a minute, and any imbalance or looseness turns that spin into shaking. The parts that rattle are often small: a filter that sits loose in its track, a baffle knocking on its neighbor, the chimney cover's upper and lower sections touching, a light lens with a broken clip, a damper flap chattering in the duct, a screw that backed out of the canopy. The shaking itself usually starts at the blower: a wheel with a lopsided crust of grease, a bent or missing blade, a motor whose rubber mounts hardened and cracked. Shaking matters beyond the noise because it slowly works everything loose, including the screws and brackets that hold the hood to the wall, the ceiling or the cabinet. That is why a hood that shakes more each month deserves a look before it starts pulling away, and why a hood that has begun to move should be treated as urgent on its own page. Tightening the upper chimney cover or reaching into the blower housing from a ladder is not something to try; the parts are reached with the power off, from the right position.