DIAGNOSIS The filters are clogged. The NV352 has two main filters: the foam filter and the felt filter behind the dust cup. Both need regular washing.
FIX Remove the dust cup. Take out both filters. Rinse them thoroughly under lukewarm water until the water runs clear. Squeeze, don’t wring, the foam filter. Let both air dry for at least 24 hours. Do not operate the vacuum without them.
IF THAT DIDN'T WORK Check the pre-motor filter. It’s a small white felt pad located where the hose attaches to the back of the pod. It’s often forgotten and can become completely matted.
HEADS UP Never put wet filters back in. Moisture will be sucked into the motor and cause corrosion or an electrical short.