Sera rotor for X-Edge 450

Rotor for the sera X-Edge corner filter, one piece.

What it fits: the sera X-Edge 450 corner filter. The range has three sizes and this part belongs to the 450 specifically – the filters deliver 450 l/h and draw 5 W, so the bodies and their parts differ in size and are not interchangeable.

What it does: the rotor is the only moving part in the filter. A magnet drags it round and the impeller pushes water through the filter media. Everything else in the filter is static, so when the flow falls off or the unit starts rattling, the fault is almost always the rotor or its shaft.

When you need it: when the blade edges have worn round, the shaft has bent or the magnet section has cracked. It is worth dissolving any limescale off the shaft before ordering a new one – cleaning often solves it.