One of the key aspects of 3D printing is temperature control as every filament and setup may require different temperatures, so it can be a big problem when your printer’s temperature starts to fluctuate.
That’s why I wrote this article to help you fix your 3D printer temperature fluctuations, so keep reading for more information.
How to Fix 3D Printer Temperature Fluctuations
Here are the main ways to fix 3D printer temperature fluctuations:
Re-secure thermistor and check the wiring
Replace the thermistor
PID Autotune
Install a smooth capacitor
1. Re-secure Thermistor and Check the Wiring
One way to fix 3D printer temperature fluctuations is to re-secure the thermistor. A thermistor is the most typical tool used on 3D printers to measure temperature.
It’s important to re-secure it because if the thermistor glass bulb isn’t properly seated, the printer’s nozzle temperatures will continuously fluctuate around the fixed temperature.
This happened to one user as his thermistor wires weren’t being held by the screw very effectively, which meant the glass bulb wasn’t fully seated in its slot. That caused temperature fluctuations, making his printer go up to 205°C then drop to 165°C without ever getting stable.
His problem was resolved after repositioning the thermistor and firmly securing it with the screw. Now his printer is able to keep the temperature stable at 200°C.
Another user was experiencing fluctuations of ± 10°C which were causing a lot of problems on his prints. After re-securing the thermistor and tightening the screw, his problem was fixed.
This fix helped many users solve their temperature fluctuation problems, as it is very easy for the screw tightening the thermistor to come loose. Remember to also check the thermistor wires for loose connections as that may also be the cause of temperature fluctuations, as noted by one user.
Another user had a problem with the screw that secures the thermistor being too tight resulting in a poorer thermal response. After loosening up a bit and making sure the cables were working, he was able to fix his problem.
You can also install a Silicone Sock around your nozzle if you don’t already have one.
2. Replace the Thermistor
Another way to fix temperature fluctuations on your 3D printer is to replace the thermistor. That’s because one of the main causes of temperature fluctuations on 3D printers is the thermistor going bad.
One user said that he was able to fix this problem in only ten minutes by replacing his thermistor, which was not working anymore.
Another user who experienced several failed prints because of temperature fluctuations finally bought a new thermistor and his problem went away. He also stated that replacing it was a quick and easy job.
Users recommend this thermistor since it’s a perfect replacement and it’s easy to install. Simply plug it into the motherboard, screw the wire into the hot end, and you’re ready to go.
Check out the video below to see full instructions on how to replace your 3D printer thermistor.
3. PID Autotune
Another popular fix to stop your 3D printer from fluctuating temperature is running a PID Autotune, which is a feature included in most 3D printers.
You can find the PID Autotune option on the Ender 3 by going into the “Control” menu and then into “Configuration” and “Advanced Settings” on the LCD. Now just set the temperature you’re mostly looking to use and wait a couple of minutes.
It will make your printer repeatedly warm and cool the hot end, to find the ideal setting for the heating element part.
After that’s done, don’t forget to go into your configuration menu and “Store Settings” so your changes are saved for the next time you restart your printer.
This option might not be available on all types of firmware though because they can have different options in the menu.
One user was suffering from unstable temperatures after installing a micro-swiss all-metal hot end. It caused his 3D printer’s temperature to fluctuate between 222°C and 237°C, rather than holding at 230°C as it was supposed to.
After running a PID Autotune, his 3D printer came back to normal and his temperature fluctuations stopped.
You can follow the video below by BV3D to run PID Autotune on your 3D printer.
Another user was experiencing temperature fluctuations between 238°C and 260°C while printing ABS. His fix was a PID Autotune, which helped keep his temperature at a stable 250°C.
Be sure to check your thermistor as mentioned in the previous section, as one user tried doing a PID Autotune to no avail. He found out the problem was a loose screw holding the thermistor which was causing an unstable temperature.
If you cannot find the PID Autotune option in your menu, you can edit your firmware and find the line “#define PID_AUTOTUNE_MENU” in “configuration.h”.
Then you’ll need to remove the # from the beginning of that line. Once you’ve flashed it to your printer, you’ll find the option located inside the “Advanced Settings” menu. This is a more advanced process though, but you can learn the process from the video below.
4. Install a Smooth Capacitor
If running a PID Autotune didn’t help and the thermistor is not the issue, you should consider installing a smooth capacitor to help you fix your temperature fluctuation problem.
A Smooth Capacitor is a capacitor that acts to smooth or even out voltage fluctuations, which can cause unstable temperatures when printing. Capacitors are made of two conductors that are close to one another and are isolated from each other. They are devices used to store electrical energy.
This fix is really popular among people who’ve done mainboard upgrades, as this is common with a few different boards such as the MKS Gen-L.
That’s because the combination of the voltage regulator and smoothing capacitor of boards like these end up causing different temperature fluctuations. Thankfully, that can be easily solved by adding another capacitor to the system.
Installing your new capacitor is very easy and won’t even require a solder.
One user was experiencing a lot of temperature fluctuations after upgrading his board to an MKS Gen-L and was able to solve his problem by adding a smooth capacitor and doing a PID retune.
Another user who built his 3D printer from scratch using an MKS Gen-L board also fixed his unstable temperature issues by adding a 1000uf capacitor.
Check out the video below for the step by step on how to add a new smooth capacitor to fix your temperature fluctuations.
How to Fix Ender 3 Not Maintaining Temperature
Here’s how to fix the Ender 3 not maintaining temperature:
Set the correct power supply voltage
Replace the heater cartridge
Turn off economy mode
1. Set the Correct Power Supply Voltage
One way to fix your Ender 3 not maintaining temperature is making sure you’ve set the correct power supply voltage.
Setting the wrong power supply voltage can lead to a lot of different problems that include your printer not being able to maintain a stable temperature, as one user found out.
After checking his power supply, he noticed the voltage was set to 230V and not 115V, causing his printer to be unable to maintain temperature.
To check if your voltage is correct, turn off the printer and check that the switch on the power supply is set to the appropriate main voltage. In the Ender 3 and the Ender 3 V2 the switch is red and is located at the back of the printer.
Check out the video below to see one user switching the power supply voltage on his Ender 3 V2.
2. Replace the Heater Cartridge
Another possible fix for your 3D printer not being able to maintain temperature is to replace the heater cartridge. The heating cartridge is another key component in making your printer heat up properly and they have two different output voltages, 12V and 24V.
One common mistake made by many 3D printing hobbyists is replacing their heater cartridges with the wrong voltage that does not match their power supply.
If you install a heater cartridge of 12V on an Ender 3, which has a power supply of 24V, you may experience problems with your printer’s temperature, as one user did.
Users recommend getting the Creality 24V 40W Heater Cartridge, if you own an Ender 3 or any other 24V 3D printer. They are made of high-quality material and are very easy to install.
Check out the video below for detailed instructions on how to replace the heating cartridge.
3. Turn Off Economy Mode
This method will only work for Ender 5 owners as the printer has a function called “Economy Mode” that comes automatically switched on.
This function will make the heated bed temperature cool down to save energy, causing the printer to not maintain temperature, generating a lot of different problems on the prints. A few different users experienced this problem without knowing that the “Economy Mode” was a default setting.
After turning it off, they fixed their issues.
To turn off “Economy Mode” simply start the print, then tap on “Adjust”, then go to “Economic” and disable it.
The CR-10S also features a very similar default setting named “Economic” which you can find in the “Adjustment” screen, middle left under the “Z-axis Compensation”.
When turned on this function may cause the CR-10S to not maintain its printing temperature generating a lot of different problems with the print.
Michael Dwamena is the founder of 3D Printerly, a platform dedicated to simplifying 3D printing for hobbyists and professionals alike. Owns over 20 3D printers (filament and resin) and has plenty experience 3D printing. Michael has authored over 900 articles, helping millions navigate the exciting world of 3D printing.
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