Can You Leave a 3D Printer on Overnight (All the Risks)


Key Takeaways

  • Fire and electrical hazards: 3D printers can overheat, short circuit, or ignite flammable materials. Enclosures and smoke detectors can help prevent fires.
  • Fume intoxication: 3D printers emit toxic fumes that can harm your respiratory health. Ventilation and filtration are essential for safe printing.
  • Failed prints: 3D printers can encounter various errors that can ruin your prints, such as filament runout, layer shift, or nozzle clog. Monitoring and pausing are recommended for long prints.
  • Noise disruption: 3D printers can produce loud and high-pitched noises that can disturb your sleep or your neighbors. Quieter models and soundproofing can reduce the noise level.

Printing overnight is not safe, and virtually all manufacturers advise against it. It involves the risk of fire and electrical hazards, fume intoxication, and failed prints from mechanical failure and filament running out. To top it all off, printing overnight can be loud and disruptive.

Typical 3D prints take a few hours, with some going over the 10-hour mark. It can be tempting to leave a printer running overnight so you can wake up to a beautiful, finished print.

I’ve personally thought about doing an overnight print, too. But there are some major risks, and I eventually decided that it just wasn’t worth it.

My own experience aside, this article will focus on all of the objective reasons why you probably shouldn’t leave your 3D printer running overnight.

Failed print left overnight
Source: Reddit. An example of a badly failed print, which can happen if you leave your 3D printer running overnight without monitoring it.
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7 Risks of 3D Printing Overnight

  • Fire Hazard
  • Electrical Hazard
  • Toxic Fumes
  • Filament Run-Out
  • Failed Prints
  • Mechanical Failure
  • Noise Pollution

Fire Hazard

A 3D printer fire hazard that was set on fire and burned.
Source: Reddit. A burnt 3D printer that set on fire.

A 3D printing fire hazard is rare, but it can still happen. There have been a few reported cases of 3D printers causing devastating fires, and most of the causes are similar.

Typically, the extruder is the culprit of 3D printing fires because of how hot they get. The hot end temperature can reach up to 300°C, depending on your filament and printer.

Heated beds are another major risk factor. Most 3D printers have heated beds that can reach similar— but slightly lower— temperatures than the extruder.

Back-to-back long printing sessions that don’t allow the hot end to cool can cause overheating. There have also been cases when an extruder gets stuck in one place during printing, causing the motors to jam and overheat. 

An overheating extruder can create a fire hazard if it comes into contact with a flammable material in its vicinity, such as a curtain or paper towel. Some filaments like ABS are also flammable and can create a fire hazard when they heat up uncontrollably. Always keep your 3D printer away from flammable objects. 

Electrical Hazard

Electrical hazards are a possible risk during overnight printing because you won’t be able to keep an eye on the state of your printer.

They happen as a result of poor electrical wiring, installation, or old wires where you’re printing. In addition, overheating can cause the wires inside your printer to get so hot that they melt the insulation around them.

All those factors are a recipe for a short circuit, which can destroy your printer or put you at risk of electric shocks and burns.

Toxic Fumes

3D printing should always happen in a well-ventilated room. During printing, filaments melt and release harmful fumes that you may sometimes not even notice.

If your printer is running overnight and you’re sleeping in the same room, you increase your exposure to these toxic fumes.

A well-ventilated room to prevent fumes from being toxic in your 3D printing area.
Sample of well-ventilated room. Source: Reddit

Some filaments like PLA have vapors that are safe to inhale, but it’s something you’re advised not to do in the long term. Others are not that safe because they give off dangerous volatile organic compounds that can have grave consequences on your respiratory health, including cancer.

For example, ABS releases Styrene, a noxious compound known to be carcinogenic. Nylon fumes are also highly toxic, causing headaches, eye irritation, and breathing problems in some individuals.

The best way around this is to make sure that your room is properly ventilated to allow fresh air in and the filament fumes out. You can also buy a 3D printer enclosure to make sure you’re completely safe from the noxious fumes, or just buy an already enclosed 3D printer. 

Filament Run-Out

It’s always disappointing to come back to your 3D printer expecting a finished item, only to find it not even halfway. And if you don’t have a filament run-out sensor to detect when you’re out and pause printing, you’ll ruin your print.

Filament Runout Sensor
A filament runout sensor. Source: Reddit

If you’re 3D printing overnight, chances are high that you’re dealing with a sizable print. These normally require a great deal of 3D printing filament. For example, a generic helmet will probably take you about 2.5 kg of filament to complete. 

If you start such a project with a 1kg spool of filament, you’ll need to mount a new one at some point, something that’s impossible to do while you sleep.

Let’s say you’ve covered your bases and predicted that the filament will not be enough for the night. It’s pretty hard to know at what particular time of the night your project will need fresh filament. There’s also a chance that you might miss that reminder alarm.

Failed Prints

Overnight Failed Prints
An overnight failed print. Source: Reddit

Speaking of unfinished prints, 3D printing overnight can increase the chances of getting a failed print. When you’re printing something for that long, there are no guarantees that your session will go as expected, even with the best 3D printers.

The most common mishaps usually happen due to first-layer issues, so starting a project and not monitoring it for the first hour or two can lead to a disastrous finish. Prints can also topple off the print bed, layers can misalign, and your nozzle can get clogged.

All these will go unnoticed through your sleep, and your print will get botched and your filament and power wasted.

Mechanical Failure

Extruder grinding

A 3D printer mechanical failure can happen anytime. If you’re not there to check on your printer, the whole printing session can go haywire.

Common mechanical issues that can occur include:

  • Extruder grinding/crushing filament
  • Clogged nozzle
  • Odd clicking noises

A telltale sign of a mechanical fault in your 3D printer is your filament not feeding properly. You can normally fix it if you spot it early, but if it goes unnoticed, the print will fail and the printer will over-exert itself, which can lead to more damage.

Noise Pollution

Most entry-level printers will give off some level of noise that is noticeable at night. Many of them run at about 55 decibels, which is the equivalent of the noise from an air conditioner.

But the thing is, this noise is considerably high-pitched and therefore more perceivable by the human ear. When everything is quiet at night, the whizzing and whistling of the motors can be uncomfortable for you and possibly your housemates or neighbors. 

Several factors affect the quietness of a 3D printer, including its stepper motor drivers and whether it has an enclosed print area. Some printers are generally noisier than others, and we’ve also written about both eliminating noise during printing, and the best quiet 3D printers. 

Tips on Completing a Longer Print:

As you might have noticed, there are many small changes or printer mods you can use to keep yourself reasonably safe.

Longer prints always have more risks. These tips will help you minimize those risks and complete your next long prints consistently and safely.

Pause Prints

Pause and resume print can be one of the most impactful features if you’re completing long prints. It’s typically used for short periods of time to refill filament or add a non-filament part to the print.

It comes with some major downsides, though.

For one thing, pausing your printer doesn’t necessarily remove the risk of fire. That’s because the pause feature often stops the extrusion of filament, but doesn’t sufficiently cool down the entire printer.

Your heated bed will still have power running through it during a pause. It’s a fire hazard so long as your printer is continuing to heat it.

Your printer might have an alternative stop feature in addition to a pause. While this could potentially remove the risk of fire, it also has a high chance of messing up your print.

Your model might shrink slightly as it cools, or it might cause a slight amount of layer shift. ABS in particular needs to be heated consistently because it’s prone to shrinking and cracking.

Despite it all, pause/resume features are a must-have for longer prints. They’re even more helpful if you use software like Octoprint to monitor your 3D printer remotely.

Printer Settings

A long print usually means a large print, and larger models can magnify even minor issues. Before anything else, you need to ensure the printer is properly calibrated.

Pay extra attention to the usual details, like print speed and layer height. Make sure your filament spool will feed properly.

It could even be worthwhile to double check your model in your slicing software, just so that you can feel certain there are no errors in the design.

Smaller Prints

Planning ahead is going to be your long print savior. For large 3D printing projects, it’s suggested to break the model into multiple smaller prints.

This reduces the consecutive printing time and avoids the problems that come with extended printing altogether.

You can assemble the small individual prints after the fact as part of post-processing. Typically, superglue or plastic model glue will be used to join the prints together.

I suggest using plastic glue if you can. It melts the plastic slightly, fusing the two pieces together seamlessly as it dries.

If You Insist On 3D Printing Overnight

While I would never recommend 3D printing overnight, especially not to beginners, I also understand that it’s very tempting.

If you do decide to run your printer while you’re gone or overnight, here are the precautions you should take.


A suitable enclosure is the best accessory to suppress potential fires. Fireproof and flameproof boxes can protect most brands of 3D printers, making them ideal for many hobbyists.

The Creality Fireproof 3D Printer Enclosure is designed for usage with most Creality printers, so long as they fit inside the zip-up tent. It’s a relatively easy solution that requires extremely little setup.

While manufactured enclosures are highly effective, they can be pricey or not designed how you want. You can always make a DIY 3D printer enclosure at a fraction of the price. In that article, we also recommend some more pre-made enclosures if the Creality one isn’t for you.


Enclosures are amazing, but they can actually encourage overheating if you aren’t careful. Ensuring proper ventilation goes hand in hand with using an enclosure.

Proper ventilation means having a vent that leads directly outside. It should be secured so that the vent is airtight, and everything inside the 3D printer enclosure goes outside.

Even putting the risk of fire aside, overheating inside of an enclosure can cause other issues. It can reduce the lifespan of electronic parts and printer motors and cause a buildup of toxic fumes in your home.

The internal temperature inside the enclosure of an FDM printer should be between 38°C (100°F) and 42°C (107°F).

Fire Detection Systems

A smoke detector already installed somewhere in your room might not detect the fire immediately, since it starts very small. Household smoke detectors usually work with ionization which is slower to detect these fires.

Your current smoke detector will eventually catch the smoke and alert you if the fire progresses, but it might have grown out of control by that point. Photoelectric smoke detectors are more sensitive to the small, smoldering type of fire that a 3D printer would start.

The other option is to purchase a new smoke detector and install it within 10 – 12 feet of your 3D printer.

You could use an automatic extinguisher mounted above the 3D printer, which would make it safer to leave the house while printing.

Camera Monitoring

Setting up a camera is an easy and effective safety measure. Plus, it offers a way for you to know when print failures arise even from a remote location.

You can check the camera periodically during the night or even while you’re gone for the day.

The Logitech C270 fulfills that requirement without being a huge wallet drain.

Another option is the Jun-Electron 5MP. It’s a 1080P Video Camera Module for the Raspberry Pi 4. If you’ve been interested in using the Raspberry Pi before, now might be the time to grab one.

How long can you safely run a 3D printer?

Theoretically, there’s no limit to how long you can run a good quality, reliable 3D printer for. Some makers have reported doing 3-day-long printing sessions without any trouble, but such long hours require monitoring and fire safety precautions.

Can you run a 3D printer 24/7?

Yes, most 3D printers can run constantly 24/7. However, it’s important to keep checking on your printer to make sure there’s been no print error, you haven’t run out of filament, and that there are no mechanical issues or fire risks.

Can I sleep with a 3D printer in my room?

It’s not safe to sleep with a running 3D printer in your room. Some of the risks involved include fire hazard, electrical hazard, and the potential to inhale toxic fumes over extended periods of time.

Safety aside, you will also need to contend with the loud noise (even with quieter printer models). And if your print goes wrong during the night, you might not realize until it’s too late.

What’s Changed?

What’s Changed In This Article?

As 3D printing technology rapidly evolves, we want to make sure we provide the most up-to-date information to our readers.

This article has been thoroughly reviewed and updated on October 22, 2023 with significant changes:

  • Adding guidance on best practices for completing longer prints successfully
  • Incorporating new tips for those who still choose to print overnight, to reduce risks
  • Overall, comprehensively updating the article with the latest recommendations on how to approach extended 3D printing jobs safely and effectively


“Our printers don’t just print objects, they print ‘oops’, ‘ah-ha’, and ‘not again’ moments.”


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Meet the mastermind behind GCode-Guru, a 3D printing wizard whose filament collection rivals their sock drawer. Here to demystify 3D tech with a mix of expert advice, epic fails, and espresso-fueled rants. If you've ever wondered how to print your way out of a paper bag (or into a new coffee cup), you're in the right place. Dive into the world of 3D printing with us—where the only thing more abundant than our prints is our sarcasm.


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