Creality Filament runout sensor

You start a 14-hour print before bed, and by morning the spool ran dry at hour nine. The nozzle kept moving, laying down nothing, and the part is scrap. Or the printer keeps stopping with a "filament runout" error while the spool is still half full. Both problems lead back to one small part, the filament runout sensor.

This genuine Creality filament runout sensor, part number 4001090034, is the factory photoelectric detector for the K1 series, Ender-3 V3, Ender-3 V3 Plus and Ender-5 S1. It watches the filament as it enters the printer and pauses the job the moment it runs out or snaps.

Load a new spool, resume, and finish the print.

Genuine Creality Part 4001090034 | Photoelectric Detection | Auto-Pause on Runout or Breakage | Indicator Light | Plug-in Factory Replacement | Fits K1, K1C, K1 Max, K1 SE, Ender-3 V3 and V3 Plus | 24 g

Who the Creality filament runout sensor is built for

Hobbyist Makers running long overnight prints

Your sensor stopped detecting runouts, or it fires false alarms that keep pausing good prints. Swapping in a genuine replacement restores the factory behaviour without touching your printer's settings. Once it is fitted, you can start a 300 mm cosplay helmet piece on a Creality K1 Max 2025 3D Printer before bed and know the printer will wait for you if the spool runs out, rather than finishing the job in mid-air.

Small print farm operators

With several printers running unattended, one empty spool can waste a full plate and hours of machine time. A working sensor on every machine turns a failed job into a pause you clear in two minutes. Keep one or two spare sensors on the shelf, and a broken unit on a Creality K1C 2025 3D printer becomes a five-minute swap instead of a printer standing idle for days.

Schools and makerspaces

Shared printers get loaded by many hands, and partly used spools are common. A runout sensor means a learner's project pauses safely when the spool ends, instead of failing after a whole lesson of printing. On an Creality Ender-3 V3 Plus 3D Printer, a teacher can load a fresh spool at break time and resume a 300 mm tall model from the same layer.

What sets this Creality filament runout sensor apart

It saves the print, not just the filament

Without a sensor, a printer cannot tell that filament has run out. The stepper motors keep moving and the G-code keeps running, so the part is ruined. When the filament end passes through this sensor, the printer firmware pauses the job, parks the toolhead and shows a runout prompt on the screen. You load a new spool, purge, and resume from the same layer. On a 20-hour job, that is the difference between losing a few minutes and losing the whole print.

Photoelectric detection with no contact parts to wear

Creality lists part 4001090034 as a photoelectric filament break detection kit. A light beam inside the housing is interrupted by the filament, so the sensor detects its presence without a mechanical switch arm that wears or sticks over time. That makes detection consistent across PLA, PETG, ABS and TPU, and it reacts to a snapped strand as well as an empty spool. An indicator light on the housing shows at a glance whether the sensor sees filament.

A direct, plug-in factory replacement

This is the same sensor Creality fits at the factory, so the housing, mounting and connector match the original. You remove the old unit, plug in the cable and refit it, with no soldering and no changes to the printer configuration. On the K1 series and Ender-3 V3 series, which run Creality's Klipper-based firmware, the sensor works with runout detection switched on in the printer settings.

One part across the K1 and Ender-3 V3 families

The same sensor fits the K1, K1C, K1 Max, K1 SE and their 2025 versions, as well as the Ender-3 V3, Ender-3 V3 Plus, Ender-5 S1, Ender-5 Max, Sermoon D3, Sermoon D3 Pro and CR-200B Pro. If you run a mix of these printers, one spare sensor covers them all. Note that the Ender-3 V3 SE and Ender-3 V3 KE use a different detector kit, so this part is not the correct replacement for those two models.

A quick way to diagnose runout faults

False runout alarms with filament loaded, or no pause when the spool is empty, are common complaints on Creality forums. A known-good sensor isolates the cause quickly. If the fault clears with the new sensor, the old one had failed. If it persists, check the cable and connector, then the board. Having a genuine spare in hand turns a guessing game into a 10-minute test.

Full specifications: Creality filament runout sensor 4001090034

Ordering, shipping and support for the Creality filament runout sensor

We courier this Creality filament runout sensor to any address in South Africa, or you can collect it from our Centurion or Boksburg store. Genuine Creality parts are covered against manufacturing defects, with claims handled locally by our technical support team. Extruders, hotends and boards for the same printers are in our Creality spare parts section.

Frequently asked questions about the Creality filament runout sensor

Will this sensor fit my Ender-3 V3 SE or Ender-3 V3 KE?

No, the Ender-3 V3 SE and KE use a different Creality detector kit with their own mounting. This part fits the K1 series, Ender-3 V3, Ender-3 V3 Plus, Ender-5 S1, Ender-5 Max, Sermoon D3 and CR-200B Pro. For K2 Plus printers, use the Creality K2 Plus Material Break Detection Module.

My printer says "out of filament" with filament loaded. Is the sensor faulty?

It may be, but test before you buy. Check the indicator light with filament inserted, reseat the cable, and make sure the filament end is cut cleanly. If the alarm continues with the sensor unplugged and runout detection switched off, the fault is in the cable or board, not the sensor.

How long does it take to replace?

Most users swap it in 10 to 15 minutes with basic hand tools. Unload the filament, unplug and remove the old sensor, fit the new one, reconnect the cable and reload. Then insert filament and confirm the indicator light responds before you start a print.

Does the sensor need any maintenance?

Very little, as it has no mechanical switch to wear out. Keep dust and filament shavings out of the filament path, especially when you use cardboard spools, which can shed fibres. A short blast of compressed air through the inlet every few months keeps the optical path clear.

Is this a genuine Creality part, and is there local support?

Yes, this is genuine Creality part 4001090034, the same sensor fitted at the factory. We hold stock in South Africa, ship nationwide and handle warranty claims locally, so you do not need to deal with an overseas supplier if a part is faulty.