- 3D printers
- 3D printer
0300-0200-0001-0007
Bambu Lab 0300-0200-0001-0007 on a 3D printer: nozzle sensor open
Risk level
High
Professional inspection is recommended.
Urgency
Medium
Quick answer
Bambu Lab HMS 0300-0200-0001-0007 means the nozzle NTC sensor looks open circuit and the printer cannot read its temperature. Switch off, let it cool, check the silicone sock and the NTC cable and, if it continues, open a ticket.
Safety first
Stop and check this first
- Do not disable or bypass the thermal protection or change the firmware to clear the alert: it is what cuts the heat when the temperature does not add up. Do not open the printer's power supply or mains board: anything at mains voltage is for the service team.
- The nozzle runs very hot: Bambu Lab asks you not to touch it and to switch off and unplug the printer before any maintenance. Wait for the toolhead to cool before putting your hands near it.
Safe checks you can perform
- Switch off and let it cool
- Hotend silicone sock
- Reconnect the NTC cable
- Support ticket with photo or video
Leave these tasks to a qualified professional
- Do not attempt this professional task: NTC and heater measurement
- Do not attempt this professional task: Hotend removal and wire check
- Do not attempt this professional task: TH board 10 pin connector or FPC
What a technician must be able to justify
Technician visit
These are the steps they must carry out and show you. Tick them as they work: if steps are skipped, do not accept a part swap.
These are not instructions for opening or handling the equipment yourself. They are the checks that should support a technical conclusion.
NTC and heater measurement
What they doThe technician measures the NTC with a multimeter (about 100 kilohms on P1 and A1, 50 to 100 kilohms on the X1) and the heater (about 12, 10 or 7 ohms for X1, P1 or A1).
They must show youthe NTC reading against Bambu Lab's value.
In writingthe measurements and what is replaced.
Hotend removal and wire check
What they doThe technician removes the hotend following Bambu Lab's guide and checks whether the sensor or its wire is broken.
They must show youthe break or the damaged sensor.
In writingthe part replaced.
TH board 10 pin connector or FPC
What they doWith a V8 TH board, the technician replugs the 10 pin connector and looks for burn marks; with V9, they reseat both ends of the FPC.
They must show youthe state of the connector.
In writingwhat was checked and whether the TH board was replaced.
Before accepting a part or repair
Nothing has been shown yet. Do not accept a part swap based on the code alone.
Follow these steps
Note: Follow the documented order. An error code identifies the affected system, but it does not prove by itself which part has failed.
Switch off and let it cool
- Who:
- you.
- How:
- switch the printer off and unplug it, as Bambu Lab asks before any maintenance, and wait for the nozzle to be cold.
- Result that matters:
- toolhead cold and without power.
- If the screen still shows heat:
- keep your hands away for now.
- If it is cold:
- move on to the silicone sock.
- Evidence to keep:
- time of the alert and a photo of the screen.
Evidence: Bambu Lab Wiki: HMS_0300-0200-0001-0007: The nozzle temperature is abnormal, the sensor may be open circuit.
Hotend silicone sock
- Who:
- you.
- How:
- with the printer cold, check whether the silicone sock is missing, has fallen off or is badly damaged. Bambu Lab says that if it is intact and can be refitted without coming loose, you can resume.
- Result that matters:
- state of the sock.
- If it is intact and fitted:
- resume the print and see whether the alert returns.
- If it is missing or broken:
- it needs replacing.
- Evidence to keep:
- photo of the sock.
Evidence: Bambu Lab Wiki: HMS_0300-0200-0001-0007: The nozzle temperature is abnormal, the sensor may be open circuit.
Reconnect the NTC cable
- Who:
- you, if you follow the guide for your model.
- How:
- with the printer off, plug the NTC cable back in, lining the plug up with its slot, as Bambu Lab stresses.
- Result that matters:
- whether the alert disappears when switching on.
- If it disappears:
- it was a poor contact.
- If it returns:
- go to the technician's measurement or to support.
- Evidence to keep:
- photo of the connector.
Evidence: Bambu Lab Wiki: HMS_0300-0200-0001-0007: The nozzle temperature is abnormal, the sensor may be open circuit.
Support ticket with photo or video
- Who:
- you.
- How:
- if the alert stays, open a technical ticket with Bambu Lab and include a photo or video of the problem and the HMS code, as the article itself asks.
- Result that matters:
- support has the code and the evidence from the first message.
- If they ask for more data:
- add the printer log and the exact model.
- If they propose a spare part:
- ask which test justifies it.
- Evidence to keep:
- ticket number, photos and video.
Evidence: Bambu Lab Wiki: HMS_0300-0200-0001-0007: The nozzle temperature is abnormal, the sensor may be open circuit.
Still not solved
If the error persists, stop here. See what the technician must do and show you.
Where this code applies
A code is meaningful only inside the right product and version context.
Primary scope
- System
- 3D printers
- Brand
- Bambu Lab
- Product type
- 3D printer
Known code variants
- 0300 0200 0001 0007
- Bambu Lab nozzle sensor open circuit
- Bambu Lab sensor boquilla circuito abierto
- HMS_0300-0200-0001-0007
What it means
According to Bambu Lab, nozzle control has a heater and an NTC sensor. If the NTC is open circuit, the TH board cannot get the right nozzle temperature, the heater may heat continuously and the print fails. The causes it gives are poor contact between cable and connector, a broken NTC or a broken sensor wire. The NTC is 100 kilohms at 25 °C and its resistance rises in the cold and falls in the heat, so small differences when measuring are normal.
Warnings and stop conditions
- Criticaleditorial warning
Do not disable or bypass the thermal protection or change the firmware to clear the alert: it is what cuts the heat when the temperature does not add up. Do not open the printer's power supply or mains board: anything at mains voltage is for the service team.
Evidence: Bambu Lab Wiki: HMS_0300-0200-0001-0007: The nozzle temperature is abnormal, the sensor may be open circuit.
- Highsource verified
The nozzle runs very hot: Bambu Lab asks you not to touch it and to switch off and unplug the printer before any maintenance. Wait for the toolhead to cool before putting your hands near it.
Evidence: Bambu Lab Wiki: HMS_0300-0200-0001-0007: The nozzle temperature is abnormal, the sensor may be open circuit.
Symptoms and causes
Probable causes · in order
- Poor contact between cable and connectorCommon
If the NTC connector is not seated properly, the TH board loses the signal; Bambu Lab lists it first.
Evidence: Bambu Lab Wiki: HMS_0300-0200-0001-0007: The nozzle temperature is abnormal, the sensor may be open circuit.
- Broken NTC sensorPossible
If the NTC is broken, the reading disappears even with a good connector; it is confirmed when removing the hotend or measuring it.
Evidence: Bambu Lab Wiki: HMS_0300-0200-0001-0007: The nozzle temperature is abnormal, the sensor may be open circuit.
- Broken sensor wirePossible
An NTC wire broken along its length leaves the circuit open just like a broken sensor.
Evidence: Bambu Lab Wiki: HMS_0300-0200-0001-0007: The nozzle temperature is abnormal, the sensor may be open circuit.
Virtual technician
Does 0300-0200-0001-0007 still appear after these checks?
Answer a few questions to narrow down the likely cause and the safest next action. Guidance only - it never replaces a professional.
Sources and technical references
- 1
Bambu Lab Wiki: HMS Home Page, List of Error Codes for Bambu Lab 3D Printers
Bambu Lab · 2026 · official_doc
- 2
Bambu Lab · 2026 · official_doc
Was this entry useful?