Magnetic Impeller Assembly for FX2 FX4 Canister Filter

This genuine Fluval Magnetic Impeller Assembly is a high-quality, direct-fit replacement for its matching FX-series canister filter.

For Fluval FX2 FX4 Filters.

Genuine Fluval FX4 Magnetic Impeller Assembly.
A high-quality replacement impeller designed for the Fluval FX4 High Performance Canister Filter. This original spare part restores smooth and efficient water flow, reduces noise and vibration, and ensures reliable filtration performance by maintaining proper pump operation. Ideal for regular maintenance or replacing worn impeller assemblies to keep your canister filter running at peak performance.

The Magnetic Impeller Assembly for FX2 FX4 Canister Filter is a replacement part for keeping your filter running at full performance — see our guide to choosing filter media for how media and hardware work together in a filtration system.

Specifications

Fluval item #A20208, UPC 015561302081. The magnetic impeller assembly for the FX2 and FX4 canister filters — the rotor, its magnet and the shaft it turns on, supplied as one assembly rather than as loose parts.

Fluval publish no dimensions for this part, and we are not going to invent any. The item number is the identification that matters: if the number on your old assembly reads A20208, this is the same part.

Compatibility

FX2 and FX4 only. That is Fluval's own compatibility statement for A20208. The FX5 and FX6 take a different assembly, item A20206, which is physically larger and comes with a bushing and bushing tool. Fitting the wrong one is the single most common ordering mistake on FX spares, and the item number on the old part is the way to be sure.

This impeller is also the one supplied inside the FX2 service kit (A20264) and the FX4 service kit (A20261).

Setup & Use

Fluval's schedule for this part: check and clean it every three months, and replace it once a year. That is from their own FX maintenance frequency chart, and the yearly replacement is preventative — the impeller wears rather than fails outright, so the symptom is a filter that has quietly lost flow, not one that has stopped.

Close the valves, unplug, then drain. Before any part of a canister filter comes off, Fluval's sequence is: turn the IN and OUT valves to the closed (horizontal) position, unplug the pump, then disconnect. The canister sits below the tank and is full of water — opening it in the wrong order empties it onto the floor, and on an FX4 or FX6 that is fourteen to twenty litres.

Rinse, do not scrub. Clean the impeller and its magnet in clean water and clear the impeller well with a small brush. Fluval are firm that no detergent or soap goes anywhere near aquarium hardware.

Silicone lubricant only. Fluval are explicit about this in both the 07 Series and FX manuals: seals and O-rings are lubricated with a silicone-based lubricant only, and they name their own Fluval Silicone Lubricant (item #A325). Petroleum jelly and vegetable- or animal-based products are not to be used, and Fluval say that using anything else voids the guarantee.

Safety & Precautions

Close the valves, unplug, then drain. Before any part of a canister filter comes off, Fluval's sequence is: turn the IN and OUT valves to the closed (horizontal) position, unplug the pump, then disconnect. The canister sits below the tank and is full of water — opening it in the wrong order empties it onto the floor, and on an FX4 or FX6 that is fourteen to twenty litres.

Unplug everything in the tank before your hands go in the water. That is Fluval's own instruction and it covers every appliance in the aquarium, not just this one. Grasp the plug and pull it; never yank the cord.

A spare is only as safe as the unit it goes into. Fluval's standing instructions still apply to the filter itself: the power cord cannot be replaced or cut, a unit that has been dropped or shows abnormal leakage should not be put back into service, and repairs go to an authorised service facility rather than a kitchen table.

What's in the Box

One magnetic impeller assembly. Fluval supply it as a single assembly; there is no O-ring, bushing tool or seal ring in the pack. The FX6 equivalent (A20206) does include a bushing, an O-ring and a bushing tool — this one does not.

If you also need the motor seal ring, the click-fit O-rings and the lid O-ring, the FX2 service kit (A20264) or the FX4 service kit (A20261) bundles them with this impeller.

Returns & Replacement

Returns are accepted within 7 days of delivery, provided the item is unused and in its original packaging. Manufacturer-sealed items cannot be returned once the seal is broken, and sale-priced items are not refundable.

If your item arrives defective or damaged, message us on WhatsApp with your order number — or email us, if you would rather — and we will replace it. Approved replacements are delivered within 3 to 5 business days. Transit damage is covered by insurance on every shipment. If tracking shows delivered but nothing reached you, tell us within 72 hours, which is the reporting window Indian couriers allow. Damage caused during installation or use is not covered; replacement spares for such cases are chargeable.

Full terms are on our Cancellation & Returns page.