It’s never a fun experience to see an error message on the screen of your 3D printer during the printing process, as it’s often a sign which shows that something is not operating as intended, meaning that a troubleshooting session is ahead before being able to print again.
On the other hand, we can consider the issues that result in your 3D printer throwing an error to be the lesser evil compared to those that don’t, even though they aren’t always necessarily easier to deal with, as they make it apparent that something is wrong and requires fixing as opposed to silently causing problems in your 3D printed models that you would only notice after the damage is done.
Today, we will be going through two such errors showing up with the messages Err: MAXTEMP and Err: MAXTEMP BED on the screen and immediately prompt your Ender 3 to abort the printing process due to there being a temperature-related problem, which can be dangerous to both the printer and the environment.
So, what causes the Err: MAXTEMP and Err: MAXTEMP BED errors that you can see on the LCD panel of your Ender 3?
While the Err: MAXTEMP and Err: MAXTEMP BED errors are often caused by the thermistors supplying incorrect temperature readings, in some cases, it can also be a result of the mainboard or the firmware malfunctioning and pushing the inadvertently pushing the temperatures up to dangerous levels.
Next up, we will be diving deeper into the factors behind the Err: MAXTEMP and Err: MAXTEMP BED errors and finding out how to fix these issues as quickly as possible.
What Causes the Err: MAXTEMP Error on the Ender 3 (Pro/V2)?
While the Err: MAXTEMP error does give us some clues about what the error currently taking place is related to, with the MAX referring to maximum and the TEMP referring to temperature, there isn’t a lot of information about what could be causing the problem.
In a nutshell, the Err: MAXTEMP error occurs when the temperature readings from the hotend reach levels above the safe limits and create a potentially dangerous situation, which prompts the Ender 3 to stop the printing process and cut the power going to the hotend immediately.
The first factor that can cause such a scenario is a thermistor malfunction, which can occur due to factors such as a damaged thermistor wire, a too loosely or tightly screwed thermistor, and practically anything else that would falsify the thermistor’s readings.
In this case, the thermistor reports the temperature values of the hotend to be too high even when it isn’t, causing the 3D printer to think that the hotend is reaching dangerous levels and stop the print as a result.
The other factor that can be behind the issue is a firmware or mainboard malfunction, which can occur due to reasons such as the firmware being buggy, or a component of the mainboard getting damaged.
In such a scenario, the hotend can actually end up reaching the exceedingly high temperatures that the thermistor readings show, creating a dangerous scenario where the hotend is heating up uncontrollably, which has to be stopped.
What Causes the Err: MAXTEMP BED Error on the Ender 3 (Pro/V2)?
The Err: MAXTEMP BED is essentially a variant of the Err: MAXTEMP error, but this time, the error refers to the bed temperature in specific instead of the nozzle temperature, which changes the potential culprits behind the problem.
The Err: MAXTEMP BED error is practically the same error as Err: MAXTEMP, but instead of the hotend, this time, the readings from the heated bed end up reaching dangerous temperature levels, prompting the Ender 3 to stop the printing process once again and cut the power to the heating block of the bed.
In this case, the culprits can either be incorrect readings from the heated bed thermistor, displaying high temperatures even though the bed is cold, or the heated bed actually reaching the extremely high temperatures due to problems in the firmware or the mainboard.
How to Fix the Ender 3 (Pro/V2) Err: MAXTEMP Error?
Fixing the Ender 3 Err: MAXTEMP error can be a slightly challenging process due to the many potential culprits behind the problem, with some culprits being especially technically complex due to the components involved.
The first step for fixing the Ender 3 Err: MAXTEMP error is to find out whether the hotend thermistor is malfunctioning and wrongly sending high-temperature readings or the hotend is actually heating up to dangerous levels, as each of these scenarios points towards a different culprit.
In the case that you encounter the Err: MAXTEMP error even though the hotend is cold, we recommend maintaining the hotend thermistor (check for damaged wires, loose connections, and whether it’s screwed into its place too tightly or loosely), and if the issue persists, replacing it.
On the other hand, in the scenario where the hotend is indeed heating up to the exceedingly high temperatures, our recommendations would be to flash an up-to-date version of the Marlin firmware and replace the mainboard, respectively.
As the scenario where the hotend uncontrollably reaches dangerously high temperature levels can potentially create a dangerous situation compared to a mere malfunctioning of the thermistor, we highly recommend being extremely careful.
How to Fix the Ender 3 (Pro/V2) Err: MAXTEMP BED Error?
Similar to the ERR: MAXTEMP error, the Err: MAXTEMP BED error also has a few distinct potential factors behind it, meaning that you will need to resort to trial and error unless you know what exactly is causing the error in your case.
To fix the Ender 3 Err: MAXTEMP BED error, you will first need to identify whether the bed is actually heating up to the levels that are displayed on the screen or the incorrect readings from the thermistor are causing the 3D printer to think that the heated bed is too hot even though it isn’t.
If the error occurs even though the bed is cold, we recommend checking the bed thermistor wire for any signs of damage or a loose connection and replacing it if it doesn’t seem like there are any such issues.
On the other hand, if the heated bed is getting way too hot, we recommend flashing an up-to-date version of Marlin firmware to your Ender 3 as the first step and replacing the motherboard if the issue persists.
As both the Err: MAXTEMP and the Err: MAXTEMP BED errors can be caused by a few distinct factors, finding the one that’s creating the problem for you and applying the appropriate fix may not always be the most straightforward process.
To quickly recap, both the Err: MAXTEMP and the ERR: MAXTEMP BED errors on your Ender 3 can occur as a result of two issues:
- The hotend (or bed) thermistor is malfunctioning. Due to the thermistor incorrectly supplying exceedingly high temperature values, the 3D printer has to stop the print because it thinks the temperatures are reaching dangerous levels.
- The motherboard or the firmware is malfunctioning. Due to the firmware or the motherboard malfunctioning, the heating block in the hotend (or the bed) ends up uncontrollably heating up to unsafe levels, which requires the 3D printer to intervene and stop the print before a dangerous situation occurs.
Once again, it’s worth noting that there is a vital difference between these two issues, with the hotend actually reaching dangerous heat levels in one scenario and the thermistor reporting high temperature values even when the hotend is cold in the other.
Mike started his 3D printing journey with the Anet A8 when it first came out back in 2017, and has been obsessed with 3D printers ever since. Nowadays, he primarily uses his Ender 3 to print functional parts that make his life more convenient whenever possible.