how do i clean the filters on my shark navigator nv356e? it's losing suction.

Diagnosis

The Shark Navigator Lift-Away Professional NV356E utilizes a multi-stage filtration system designed to trap fine particulates before they reach the motor. When you notice a significant drop in suction, it is typically because the pre-motor foam and felt filters have become saturated with "cake"—a dense layer of compressed dust, pet hair, and microscopic debris. This blockage restricts the cubic feet per minute (CFM) of airflow, forcing the motor to work harder and potentially causing the unit to overheat or trigger a thermal shutdown. To confirm the filters are the root cause, perform a "bypass test." Turn the vacuum on and momentarily remove the foam filter from the base. If the suction immediately increases significantly at the floor head, the filter is clogged. If the suction remains weak, the issue is likely a blockage in the hose or the brush roll assembly rather than the filtration system. You can also visually inspect the felt filter; if it appears grey or charcoal-colored instead of its original light tone, it has reached its saturation point and requires immediate maintenance.

How to Fix It

Follow these precise steps to deep-clean your filtration system and restore maximum airflow to your NV356E.

1. Access the Filters: Turn the vacuum off and unplug it from the wall. Locate the filter assembly on the dust cup. Press the release button to remove the dust cup from the main body. Locate the foam and felt filters situated at the base of the vacuum head/dust cup assembly.
2. Clean the Foam Filter: Remove the foam filter. Hold it under a stream of cold tap water. Do not use soap or detergents, as these leave a residue that attracts more dust. Run the water through the foam until the runoff is completely clear. Gently squeeze the foam to remove excess water. Crucial: Do not wring, twist, or scrub the foam, as this will tear the cellular structure and allow dust to bypass the filter and enter the motor.
3. Clean the Felt Filter: Remove the felt filter. Do not rinse this filter with water, as the felt fibers can shrink or lose their structural integrity. Instead, take the filter outside and tap it firmly against a hard surface or over a trash can to knock loose the embedded debris. You can also use a handheld vacuum or a soft brush to gently clear the surface.
4. The 24-Hour Dry Cycle: Place both filters on a flat, well-ventilated surface. They must air dry for a minimum of 24 hours. Even a slightly damp filter will act like a sponge, blocking airflow and potentially causing mold growth or permanent motor damage due to moisture intake.
5. Reinstallation: Once bone-dry, slide the felt filter back into its slot first, followed by the foam filter. Ensure they are seated flush against the housing to prevent "air leaks" that reduce suction efficiency.

If That Didn't Work

• Inspect the Hose and Wand: If suction is still low, remove the hose from the vacuum body. Drop a coin or a small ball through the hose; if it doesn't fall through instantly, there is a clog. Use a long flexible wire or a broom handle to push the obstruction out.
• Clear the Brush Roll: Check the bottom of the NV356E. Hair and string often wrap around the agitator, preventing the bristles from flicking debris into the suction path. Use scissors to cut along the length of the brush roll and pull out the debris.
• Check the Floor Nozzle: Inspect the "neck" where the hose connects to the floor head. A common failure point is a buildup of pet hair exactly where the air transitions from the head to the hose.
• Replace the Filters: If the foam filter has become brittle, torn, or remains grey after washing, it has reached the end of its life. Purchase a replacement filter set (compatible with the NV356E model) to restore factory-spec suction.

Heads Up

• Never Use a Dishwasher: Do not put the foam or felt filters in a dishwasher or washing machine; the high heat and chemicals will destroy the filtration rating.
• Dryness is Non-Negotiable: Installing a damp filter can lead to a "musty" smell and can permanently corrode the motor bearings.
• Maintenance Schedule: For homes with pets or high-traffic carpets, rinse the foam filter every 30 days and tap the felt filter every 2 weeks to prevent suction degradation.
• Avoid Scented Sprays: Never spray fabric fresheners or perfumes directly onto the filters, as this clogs the microscopic pores of the material.