Fluval 07 Impeller Cover 307/407
Water type
Freshwater + Marine
Fits
Fluval 307, Fluval 407
Part no.
A20148
In the box
1 x impeller cover
Fluval 07 Impeller Cover 307/407
The plate that keeps the impeller where it belongs.
This is the genuine Fluval impeller cover, part A20148, for the 307 and 407 canister filters. It is the moulded plate that closes the impeller well in the motor head and holds the magnetic impeller square on its ceramic shaft. Fluval lists it against model codes A446 and A449 only, so it is a two-model part rather than a range-wide one.
Key features
- Genuine Fluval A20148 – moulded to the 307 and 407 impeller well, so it seats flush and the motor head closes without forcing.
- Stops the rattle – a cracked or distorted cover lets the impeller walk sideways in its well. That knock is the noise most owners mistake for a failing motor.
- Carries the top of the ceramic shaft – the shaft is only supported at both ends. With a loose cover it chatters, and a chattered shaft eventually snaps.
- Comes off by hand – no tools, and it is already exposed at every impeller clean, so fitting adds nothing to a routine service.
Specifications
| Manufacturer part number | A20148 |
|---|---|
| Sold as | Single cover |
| Position in filter | Over the impeller well, inside the motor head |
| Fits filter model codes | A446 (307), A449 (407) |
| Water type | Freshwater and marine |
| Tools required | None |
Will it fit my filter?
The 07 Series does not share one impeller cover. The two large-body canisters share A20148; the two small-body canisters each have their own part.
| Filter | Model code | Cover part | Takes A20148 |
|---|---|---|---|
| Fluval 107 | A440 | A20113 | No |
| Fluval 207 | A443 | A20133 | No |
| Fluval 307 | A446 | A20148 | Yes |
| Fluval 407 | A449 | A20148 | Yes |
If you own the smaller pair, you want the impeller cover for the 107 or the impeller cover for the 207 instead.
Which filter is which?
The two canisters this cover suits are the large-body 07 models. Fluval publishes two flow figures for each, and the difference between them is the point: the headline number is measured on an empty canister, and the second is what the filter actually turns over with media in the baskets.
| Model | Aquarium capacity | Pump output (empty) | Filter circulation (media loaded) | Max head | Power at 240 V |
|---|---|---|---|---|---|
| 307 | 90–330 L | 1,150 L/h | 780 L/h | 1.75 m | 15 W |
| 407 | 150–500 L | 1,450 L/h | 930 L/h | 2.25 m | 20 W |
Size a tank against the circulation figure, not the pump output. Max head is the vertical lift at which flow falls to zero, so a cabinet-mounted 307 is already using part of its 1.75 m before the hoses turn a corner.
What's included
- 1 x impeller cover
Not included
- The impeller. This is the cover only – see the 307 impeller assembly or the 407 impeller assembly.
- The ceramic shaft and rubber bushings. Sold as the 06/07 impeller shaft and bushing, part A20039.
- The motor head. A complete head is a separate part.
Suitable for, and not suitable for
Suitable for a 307 or 407 whose cover has cracked, gone brittle or lost a locating tab; a second-hand canister that arrived incomplete; and anyone who has found the impeller sitting loose after a service.
Not suitable for the 107 or 207, for any 06 Series canister, or for the FX Series. It will not fix low flow caused by clogged media, a blocked intake strainer or a kinked hose – check those first, because they are far more common than a failed cover.
Care and maintenance
Take the cover off at every impeller clean and look at it in the light. Hairline cracks radiating from the locating points are the usual failure, and they show up long before the part actually breaks. Wipe the mating face clear of slime so the cover sits flat, and never refit a cover that has visibly bowed – a bowed cover holds the impeller at a slight angle and wears the shaft ends unevenly.
Goes well with
- Ceramic impeller shaft and bushing (A20039) – the part that usually needs replacing alongside a damaged cover
- 307/407 media basket cover – the other moulded part that stops water bypassing where it should not
- 07 Series primer assembly – for a canister that has stopped self-priming
Warranty and delivery
Supplied as a genuine Fluval replacement part. Your rights under the Australian Consumer Law apply in full and nothing here limits them. Fluval does not quote a separate warranty term on moulded service parts. Ships as a standard small parcel anywhere in Australia.
Common questions
Does the Fluval A20148 impeller cover fit a 107 or 207?
No. Fluval lists A20148 against the 307 and 407 only. The 107 takes part A20113 and the 207 takes part A20133, and the two are not interchangeable with the large-body cover.
Will it fit a Fluval 306 or 406?
Fluval lists A20148 for the 307 and 407 alone. The 06 Series canisters are served by their own parts list, so check your model against that rather than assuming the 07 cover carries back.
My canister has started rattling. Is the cover the problem?
It can be, but check in order: a worn or chipped ceramic shaft first, then the impeller magnet for cracks, then the cover for distortion. A rattle that changes pitch when you press on the motor head usually points at the cover or the shaft rather than the motor.
Is the cover the same as the impeller well?
No. The well is the moulded chamber in the motor head that the impeller spins inside. The cover is the separate plate that closes it.
Do I need to replace the impeller at the same time?
Not automatically. If the impeller magnet is smooth, uncracked and the vanes are intact, reuse it. Replace both when the cover has broken and let the impeller run loose, because the shaft ends will usually have worn by then.
