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Are 3D Printers at Risk of Catching on Fire?

Like all electronics that produce heat, they can malfunction, which might pose a fire hazard.

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3D printers are a revolutionary piece of electronic machinery. Still, like all electronics that produce heat, they can malfunction, which might pose a fire hazard.

3D Printers are at risk of catching fire because they use power to produce heat. If your printer overheats or malfunctions, it could quickly start a fire, and if you aren’t prepared to contain the fire, you could ruin your printer or even burn your home. 

So, let’s talk about 3D printers and fires. I’ll teach you about why a 3D printer might go up in flames, and I’ll discuss the ways that you can fireproof your 3D printer, keeping you and your home safe from fires. 

What Causes 3D Printers To Catch on Fire?

When working with any electrical machinery that produces heat, especially a 3D printer, you should prepare for fire risks. Fire risks are common in some models of 3D printers, especially those sold for lower prices. 

A 3D printer might catch on fire for one of many reasons. Some of the most common causes of fires for 3D printers are electrical overheating, a thermistor that has come loose, a thermal runaway malfunction, an extruder jam, or flammable casings. 

Let’s get into the details and talk about how these conditions could produce a fire in your 3D printer. 

Electrical Overheating

Most 3D printer-related fires are electrical fires that occur when the wires inside your printer get so hot that they melt the insulation. 

When this happens, the wires may spread heat to your 3D printer, melting the frame, filament, or structural components and eventually starting a fire from within the machine. 

Most 3D printer fires caused by electrical issues are a result of a poorly made printer. Printers with loose solder, badly insulated wires, and mis-sized wires have a high chance of going up in flames eventually. 

This means that ensuring that your 3D printer is constructed correctly or purchasing a printer from a reputable brand is the best way to prevent fires. 

The Thermistor Comes Loose

As your 3D printer prints, it heats the plastic filament to turn it into a liquid. Then it uses the extruder to squeeze the filament out, giving you a layer of printed material. 

Some 3D printers also use a heated print bed to prevent warping and control the cool-down rate of your filament. 

So, your printer will continually heat up when you print anything. Your printer has a thermistor’s temperature-reading mechanism to regulate the temperature and keep it from burning the filament. 

Thermistors use a sensor to read the temperature, and they communicate with the controls of your printer to adjust how much heat it produces. 

However, they are also secured to the printer with screws, and they use wires to connect to the control boards of your printer, and these connections are notorious for coming loose. 

When the connections come loose, your printer won’t measure the heat level accurately, which could result in overheating or a fire if you don’t manually turn the printer off and repair it. 

The Thermal Runaway Malfunctions

Filament and many of the acrylic and plastic materials used to make 3D printers are highly flammable. If the heat is allowed to increase unchecked, your printer’s casing, filament, or components could melt and eventually go up in flames. 

That’s why most 3D printers include a thermal runaway that shuts down the printer if it gets too hot. The thermal runaway is a safety feature that protects your 3D printer from going up in flames if the thermistor malfunctions or comes loose. 

However, if the thermal runaway is poorly made or cannot detect your thermistor’s heat level, you have a sure-fire recipe for flames. 

Extruder Jams

The warm extruder will move as your model prints, distributing small layers of melted filament onto the print bed. The extruder uses heat to make your model, but it could create a severe fire hazard when it has no time to cool off between layers. 

However, if your print fails and blocks the extruder from moving correctly, it can block the extruder and keep it trapped in one spot on your model.

When this happens, the extruder might heat the model so much that it starts to melt, then catches on fire. 

Flammable Casings

High-quality thermal printers can be expensive, but they are usually worth it since printers made with cheap, flammable materials often catch on fire during printing. 

Materials such as foam, acrylic, plastic, and wood are acceptable for the structural components of your 3D printer when it comes to keeping all the parts held together. That said, these flammable materials significantly increase the risk that your printer will turn into a molten pile of melted materials with use. 

How Do You Fireproof a 3D Printer? 

So, how do you avoid fires while 3D printing? I’m glad you asked. 

To fireproof a 3D printer, you should: 

  1. Buy A Printer From A Reputable Brand. 
  2. Install A Smoke Detector Above Your Printer. 
  3. Keep Flammable Materials Far From Your Printer. 
  4. Use A Fire-Retardant Filament. 
  5. Maintain Your Printer Properly. 

So, let’s talk about how you can use these methods to prevent and contain printer fires. 

Buy a Printer From a Reputable Brand

When it comes to 3D printers, a bargain isn’t always a good thing. You generally get what you pay for, which means that unbelievably cheap 3D printers are made with more inexpensive, likely flammable materials and low-quality wiring. 

So, to prevent yourself from purchasing an expensive piece of kindling, check out the reviews and ratings for any printer you are interested in. Try to find out what materials your printer is made from, and always verify that it is made with flame-retardant materials like metal, inflammable wire casings, and glass. 

Install a Smoke Detector Above Your Printer

Smoke detectors can’t entirely prevent your printer from going up in flames, but they can help you contain the fire if it occurs. 

Install a smoke detector within feet of your 3D printer and keep up with its battery life cycles for the best results. That way, you’ll be able to get to the fire before it gets to you!

Keep Flammable Materials Far From Your Printer

Keeping materials like foam, wood, plastic, sawdust, and paper far from your printer can ensure that any fires that occur go out on their own, which can protect you from a raging house fire. 

It’s best to keep your printer on a piece of sheet metal or a metal shelf with nothing else on it to prevent any fires from spreading. If there are multiple shelves, put your 3d printer in a spot so that there is sheet metal above it, which can help smother and contain fires. 

Use a Fire-Retardant Filament

Fire retardant filaments are fantastic, especially for prints that might fail and block the extruder during the print process. These filaments work just as well as other flammable filaments, but they won’t catch on fire, preventing flames from sparking or spreading. 

I always use this Polymaker Polycarbonate Flame Retardant Filament (available on, which comes in black and white, and always gives me durable prints. 

Maintain Your Printer Properly

As I mentioned above, faulty or loose thermistors are a leading cause of 3D printer fires. So, to keep your thermistor in good condition, tighten the screws regularly and check for any loose wiring. 

In addition, you may want to check the solder on the wires in your printer every once and a while to ensure that the thermal runaways and electrical wiring are secure and not burnt. 

Final Thoughts

3D printers can start fires, so it’s essential to know the causes and reduce the risk of fire hazards when using a 3D printer. Most fires are caused by electrical problems like overheated wires or melted wire casings. 

Additionally, fires can also happen if your thermistor is loose, if the thermal runaway malfunctions, if the extruder jams, or if your printer has a flammable casing. To prevent these issues, you should always maintain your printer. 

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About Ben

I started 3D printing since 2013 and have learned a lot since then. Because of this I want to share my knowledge of what I have learned in the past years with the community. Currently I own 2 Bambulab X1 Carbon, Prusa SL1S and a Prusa MK3S+. Hope you learn something from my blog after my years of experience in 3D printing.