- 3D printers
- 3D printer
0300-0100-0001-0003
Bambu Lab 0300-0100-0001-0003 on a 3D printer: bed overheating
Risk level
High
Professional inspection is recommended.
Urgency
High
Quick answer
Bambu Lab HMS 0300-0100-0001-0003 means the heated bed is hotter than the temperature you set. Stop the print, switch off and unplug the printer, do not touch the bed and open a ticket with Bambu Lab.
Safety first
Stop and check this first
- A hot bed burns. Switch off the printer, unplug it and wait for the bed to be cold before touching it or looking closely at its cables.
- 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.
Safe checks you can perform
- Switch off, unplug and let it cool
- Set temperature against actual
- Exact printer model
- Support ticket with photo or video
Leave these tasks to a qualified professional
- Do not attempt this professional task: Test of the bed power chain
- Do not attempt this professional task: AC board or mainboard replacement
- Do not attempt this professional task: Heatbed replacement
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.
Test of the bed power chain
What they doSupport or the technician separates whether the fault is in the power side (AC board, or mainboard on the A1 mini) or in the temperature reading, following Bambu Lab's isolation process.
They must show youwhich check ruled out the other path.
In writingthe path chosen and the part replaced.
AC board or mainboard replacement
What they doIf the power side fails, Bambu Lab says to replace the AC board on X1, P1, A1, H2 and P2S, or the mainboard on the A1 mini.
They must show youthe board reference for your model.
In writingthe board replaced and the heating test afterwards.
Heatbed replacement
What they doIf the reading fails, Bambu Lab says to replace the heatbed (V2 or V3 on the X and P series), which carries the temperature sensor.
They must show youwhy the power side was ruled out.
In writingthe bed version fitted and the test result.
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, unplug and let it cool
- Who:
- you.
- How:
- cancel the print, switch the printer off and unplug it, as Bambu Lab asks before any maintenance. Do not touch the bed.
- Result that matters:
- the bed stops heating.
- If the alert returns right after switching back on:
- do not start another print and go to the ticket.
- If it does not return:
- note the date and watch the next print.
- Evidence to keep:
- time of the alert and a photo of the screen.
Evidence: Bambu Lab Wiki: HMS_0300-0100-0001-0007: The heatbed temperature is abnormal; the sensor may have an open circuit.
Set temperature against actual
- Who:
- you.
- How:
- before switching off, take a photo of the screen or app showing the set and actual bed temperature.
- Result that matters:
- whether the actual reading is above the set one, which is what this alert describes.
- If the actual keeps rising with the bed set lower:
- switch off and unplug.
- If both figures match:
- tell support; it may be a reading fault.
- Evidence to keep:
- photo with both temperatures and the time.
Evidence: Bambu Lab Wiki: HMS_0300-0100-0001-0003: The heatbed temperature is abnormal; the heater is over temperature.
Exact printer model
- Who:
- you.
- How:
- check on the label or in the app whether your printer is an X1, P1, A1, A1 mini, H2 or P2S.
- Result that matters:
- the model, because Bambu Lab names a different part for each one.
- If it is an A1 mini:
- the part involved is the mainboard, not an AC board.
- If it is another model:
- the part involved in the power side is the AC board.
- Evidence to keep:
- model and serial number.
Evidence: Bambu Lab Wiki: HMS_0300-0100-0001-0003: The heatbed temperature is abnormal; the heater is over temperature.
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_0300-0100-0001-0003: The heatbed temperature is abnormal; the heater is over temperature.
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 0100 0001 0003
- Bambu Lab cama sobretemperatura
- Bambu Lab heatbed over temperature
- HMS_0300-0100-0001-0003
What it means
Bambu Lab explains this alert appears when the actual heatbed temperature is higher than the set temperature. Bed control is made up of the MC board, the AC board, the power supply and the heatbed with its sensor; on the A1 mini, the mainboard does the MC and AC work. The two causes it gives are a fault in the chain that powers the bed (AC board or mainboard), which keeps heating, or a bed sensor that reads wrongly. The code does not say which one it is.
Warnings and stop conditions
- Higheditorial warning
A hot bed burns. Switch off the printer, unplug it and wait for the bed to be cold before touching it or looking closely at its cables.
Evidence: Bambu Lab Wiki: HMS_0300-0100-0001-0007: The heatbed temperature is abnormal; the sensor may have an open circuit.
- 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_0300-0100-0001-0003: The heatbed temperature is abnormal; the heater is over temperature.
Symptoms and causes
Probable causes · in order
- AC board or mainboard not cutting the heatPossible
If the bed power chain fails, the AC board (or the mainboard on the A1 mini) keeps supplying power and the bed heats without control.
Evidence: Bambu Lab Wiki: HMS_0300-0100-0001-0003: The heatbed temperature is abnormal; the heater is over temperature.
- Heatbed temperature sensorPossible
If the bed sensor fails, the printer reads the wrong temperature, and Bambu Lab gives this as the other common cause of the alert.
Evidence: Bambu Lab Wiki: HMS_0300-0100-0001-0003: The heatbed temperature is abnormal; the heater is over temperature.
Virtual technician
Does 0300-0100-0001-0003 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
- 3
Bambu Lab · 2025 · official_doc
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