Creality CFS photoelectric board

Your K2 Plus pauses on a colour change and the screen shows FR2835: filament may be stuck from loader to CFS hub. You pull the tube, the filament is sitting right there, and it still will not load. Or the CFS insists a slot is loaded when it is empty. When the hub cannot see filament, the whole multi-colour system stops trusting itself.

The Creality CFS photoelectric board is the small sensor board at the hub outlet in the base of the Creality Filament System. It tells the CFS when filament has reached the hub, and when it has cleared it again.

Replace a faulty CFS photoelectric board and the CFS goes back to loading, retracting and swapping colours on its own.

Genuine Creality part 2101020333 | Hub outlet filament detection | Optical, no moving contacts | Fits the Creality CFS for K2 series and Hi | Clears hub detection errors | Plug-in board replacement | Local stock in South Africa

Who the Creality CFS photoelectric board is built for

The K2 Plus owner stuck on a hub error

You run a K2 Plus Combo and multi-colour jobs keep failing at the hub. If you have already cleared the PTFE path and the error comes back on a clean, free-running filament, the hub sensor itself is the likely fault. This board is the exact factory part, so a swap restores normal detection without touching firmware. Replace it in an afternoon and run a four-colour logo plate the same night.

The small print farm operator

A CFS that throws false feed errors stops a printer mid-job, often overnight, and you only find out in the morning. Keeping a spare CFS photoelectric board on the shelf turns that into a quick board swap instead of a week offline while you wait for parts. Because it is the genuine board, the replacement behaves exactly like the sensors in your other units, so your load and retract routines stay predictable across the fleet.

The school or makerspace technician

Shared printers see heavy use and a lot of hands. Filament gets forced into the wrong slot, and dust and debris build up in the base of the CFS. When a hub sensor fails, you need a cheap, specific part rather than a whole new CFS unit. This board lets you repair the unit you already own, and the CFS error codes point you straight at it, which makes it a good repair job for learners.

What sets the CFS photoelectric board apart

It is the checkpoint every filament passes through

The CFS sends up to four filaments into one hub, and from there a single PTFE tube runs to the extruder. This board sits at the hub outlet and detects whether filament is present. During pre-feeding, the feeder pushes new filament forward until the hub sensor sees it, then pulls it back slightly to tension the spool. During unloading, the CFS keeps retracting until the sensor reports the hub is clear. Every load, retract and colour swap depends on that one signal being correct.

Optical sensing that does not wear like a switch

This is a photoelectric sensor: the filament breaks a light beam instead of pressing a mechanical lever. There is no spring to fatigue and no contact to wear, which suits a part that triggers on every single filament change. Creality lists it as a detection board only, with no motor drive and no main control on the board. The CFS mainboard does the thinking, and this board simply reports what it sees.

The error codes tell you when it is the culprit

Creality's CFS error table names the hub detector directly in several faults. FR2835 means filament did not trigger the hub detector while feeding. FR2849 means the hub detector stayed triggered after the filament was pulled back. FR2850 means the hub detected filament from a slot that was not being unloaded. Each can also come from a jam or high friction in the PTFE path, so rule those out first. If the error persists with a clear path, a faulty board is the likely cause.

Know which part you actually need

The CFS and printer use several filament sensors and boards, and owners often order the wrong one. The table below shows where each part sits.

Full specifications: CFS photoelectric board

Ordering, shipping and support for your CFS photoelectric board

We ship the CFS photoelectric board by courier anywhere in South Africa, or you can collect it from our Centurion or Boksburg store. Warranty claims are handled locally by our team. Our technicians can help you work out from the error code whether you need this board or another part. We also stock Creality spare parts for the CFS and K2 series.

Frequently asked questions about the CFS photoelectric board

Is this the same as the K2 Plus filament runout sensor?

No, they are two different sensors. This board detects filament at the CFS hub outlet. The K2 Plus Material Break Detection Module detects filament at the extruder. FR2835 usually points to the hub side, while FR2836 usually points to the extruder side.

Does it work with the CFS-C for K1 printers?

No, this board is for the standard Creality CFS used with the K2 series and the Hi. The CFS-C for the K1 series and the CFS Lite have different hardware. Check which unit you have before ordering.

How hard is it to replace?

It is a simple repair if you are comfortable with screwdrivers and small connectors. Unplug the CFS and remove the PTFE tubes. Open the base to reach the hub, then swap the board and reconnect its cable. Afterwards, reload a filament to check that pre-feeding stops at the hub as it should.

How do I stop the hub sensor from failing again?

Keep the filament path clean and free-running. Trim filament ends cleanly before inserting them, and never force filament into a slot that is not being loaded. Replace worn PTFE tubes during routine maintenance, because shavings and dust in the base can block or confuse an optical sensor.

Is there local support in South Africa if I am not sure this is the fault?

Yes, submit a technical support ticket with your error code and what you have already tried. Our team will help you confirm the faulty part before you buy, so you do not replace the wrong board.