X1 and P1: clogged nozzle or hotend (0300-4006) and how to clear it

Symptom

The X1 or P1 stops extruding or extrudes little and unevenly, the filament curls when extruded by hand, or the printer reports a clogged nozzle (0300-4006 or 0300-8016). It can happen with PLA in an enclosed printer, with particle-filled filaments or when switching between very different materials.

Likely causes, from most to least likely

1. Heat creep: PLA or another filament that softens early gets soft from the heat inside the enclosed printer and forms a plug.
2. Particles in the filament (carbon fibre, glitter, glow in the dark) or dirt blocking the nozzle tip.
3. Filament with an inconsistent diameter, thicker than 1.75 mm, getting stuck.
4. Leftovers of a very different material that was not fully purged (for example PLA after PC or TPU after ASA).
5. Printing too fast (Ludicrous mode) or too cold for the material: there is no time to melt it.
6. The clog is not in the hotend but in the extruder.

Checks to tell which one it is

• Heat to the filament's temperature and extrude a little from the screen: if nothing comes out or it is hard, there is a clog.
• With the AMS disconnected and heat-resistant gloves on, open the front cover, cut the filament with the cutter, remove the two hotend screws, take the hotend out and push a filament through it by hand: if it will not pass, the clog is in the hotend.
• If the hotend is clear, extrude and retract with the extruder: if it struggles, the clog is in the extruder.
• Watch the filament as it extrudes: it should come out straight; if it curls, there is a partial clog.

Before you start

Before taking anything apart, cleaning or adjusting it, switch the printer off and unplug it, unless a step says otherwise, and do not touch the nozzle, the heater block or the bed until they have cooled down. If in any doubt about electricity, heat or moving parts, stop and ask a professional.

Step-by-step fix

1. Clear it with the needle (simple clog)

   Set the nozzle to 250 °C from the temperature and axis section of the screen and lower the bed to mid height. Wearing heat-resistant gloves and keeping your face away, insert the needle supplied with the printer into the nozzle tip and move it through a few times without pushing it too far in. Do not do this with 0.2 mm nozzles.

   Check: When extruding from the screen, the filament comes out straight without curling.

   If that does not fix it: Do a cold pull (next step).

2. Cold pull

   Remove the front cover, loosen (do not remove) the screws next to the PTFE tube support and take the tube out. Heat to 220 °C (with PLA), push filament in at the top of the extruder and extrude until it comes out. Set 100 °C, wait until it gets there and press retract while gently helping to pull, without fighting the gears. Repeat until the tip comes out clean.

   Check: The pulled tip comes out clean, with no debris.

   If that does not fix it: If the hotend is still clogged it may need replacing: check with Bambu Lab support.

3. Refit the PTFE tube

   Push the PTFE tube fully into the extruder filament sensor, raise its support as high as it will go and tighten the screws: this keeps feed resistance low.

   Check: The filament loads smoothly.

   If that does not fix it: If the filament does not advance, check the extruder (next step).

4. If the clog is in the extruder

   Switch the printer off and clean the extruder following the Bambu Lab extruder maintenance guide for your model: it has to be removed and the debris cleared from the gears.

   Check: Filament goes in and out of the extruder normally.

   If that does not fix it: Contact Bambu Lab support.

5. When switching from a high-temperature to a low-temperature material

   After printing materials such as PAHT-CF or PET-CF and before using PLA, PETG or TPU: set the nozzle to 250-300 °C, unload the material by hand, load the new one so it pushes the residue out and lower the temperature step by step to 220-240 °C while extruding until it runs clean.

   Check: The new material comes out clean and steady.

   If that does not fix it: Do a cold pull.

Prevention

• With PLA and PETG on the X1 or P1S, lower the bed temperature if you can and open the door or remove the top cover to let heat out.
• Use dry filament with a 1.75 ± 0.03 mm diameter.
• Do a cold pull at least once a month, especially if you switch materials often or use fibre-filled filaments.
• Do not print faster than the hotend can melt (careful with Ludicrous mode) and keep the silicone sock fitted.

Still not fixed?

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Printers it applies to

Bambu Lab X1 Carbon, X1, X1E, P1S and P1P.

Official sources

This guide summarises the official documentation linked here:

• Nozzle/Hotend Unclogging Procedure for X1/P1 · Bambu Lab
• How to check which part is clogged for X1/P1 · Bambu Lab
• How to Avoid Nozzle Clogs · Bambu Lab
• Error Code · Bambu Lab