How to Fix 3D Printer (Ender 3) Nozzle That Won’t Screw In


If you find that the nozzle on your 3D printer won’t screw in, whether it’s an Ender 3 or Prusa machine, you’ll want to learn how to fix this issue.

Sometimes the nozzle on your 3D printer won’t be flush, won’t screw in, or be stripped. Depending on the situation, you’ll need a good solution to get your 3D printer back up and running.

Keep on reading through this article for more information about these nozzle issues and how to fix them once and for all.

How to Fix 3D Printer Nozzle (Ender 3) That Won’t Screw In

The main methods to fix a 3D printer nozzle that won’t screw in all the way is to:

  • Install the nozzle while it’s hot
  • Clear debris and residue from threading
  • Remove clogs with heat
  • Check PTFE tube is installed properly

Install the Nozzle While it’s Hot

The first thing you want to do when trying to fix your 3D printer nozzle that is having trouble screwing in, is to make sure you tighten the nozzle only after heating it up to a fairly high temperature.

There is a significant difference between a cold and hot nozzle when talking about these tight-fitting spaces. A term called thermal expansion is at play, which is when heat actually changes the size of these parts slightly, so you need to have the nozzle heated up to compensate for thermal expansion.

In some cases, if you have been printing materials that require high temperatures, you want to make sure you warm up the hotend to that previous temperature.

This is so you can make the material inside soft enough to successfully screw the nozzle back into the heater block.

For most people, doing this simple step will work for them to fix the issue of the nozzle not screwing in all the way, whether you have an Ender 3, Anet, or Prusa 3D printer.

Clear Debris and Residue From Threading

The next thing I would try is to do a deeper clean into the actual threading of the parts that screw in.

One user who had trouble screwing his nozzle all the way into the heater block figured out that it could have been from filament residue being pushed inside the threads of where you screw the nozzle in.

This likely happened because he pushed the Bowden tube all the way through the hotend to try and clean it out. He found it hard to clean up even with the nozzle preheated, and thought he would have to purchase a new hotend.

If you find that you are still having trouble screwing the nozzle further into the heater block, you should remove the nozzle from the heater block, and heat it up to around 160°C.

Then manually push through PLA through the top end of the PTFE tube so it can flow through the normal pathway around the inside of the threads.

You want to then cool the temperature down to around 90°C and do a “reverse atomic” or pull the filament out from feeding end or from the front-end of the PTFE tube.

This should result in your filament bonding with the heated up filament, which then cools down allowing you to remove any debris or residue out from the threading. Doing this a few times might be necessary to get all the residue out.

Some people use a different “atomic pull” technique with cleaning out their hotend. They would start with a cold hotend, then start heating up their nozzle to a temperature like 185C.

They would then start pulling slowly and steadily around the 70C mark, using as much pressure as you can without pulling out the hotend mount. Once the filament starts to melt, you’ll notice that the whole thing will pop out, resulting in a cleaner hotend.

You want to repeat this a few times depending on how clogged your threads are. I haven’t tried this myself, but it sounds like it could be pretty effective.

Remove Clogs with Heat & Brushing

If you don’t want to use the atomic pull method, you could try simply heating up the hotend and trying to clean it out with a wire brush.

These can be pretty effective since they are much tougher than the plastic filament that may be left in your filament pathway. Many people use a good quality wire brush along with heat to clean out their clogs.

The OriGlam 3Pcs Steel/Nylon/Brass Wire Brush Set from Amazon is a great choice that has helped out many 3D printer users with this type of issue. These are high quality brushes that have several uses, on top of your 3D printing needs.

The Nylon Brush is great for gentle cleaning, the Brass Brush is great for metal parts like your hotend, nozzle and screw threads, and the Steel Brush is perfect for heavy duty scrubbing such as rust from metal parts.

I’d use the Brass Brush for most of this clog removal in this specific case. I’d avoid using the steel brush since it can wear out and strip the threads.

Check PTFE Tube is Installed Properly

It’s possible that your PTFE tube is getting in the way of the nozzle being able to be screwed all the way into the nozzle. It could be from heat damage that can easily affect the tubing after several 3D prints.

This usually happens if you still have the stock PTFE tube which doesn’t have the best heat-resistance. In some cases, as long as the tube isn’t too short, you can simply cut it with a sharp knife.

I’d also manually check how the ends of the PTFE tube looks since the PTFE may be trimmed to fit the entrance of the hotend, so if it is damaged, it can result in a bad fit with the nozzle.

If you want to prevent getting heat damage in the future, you’ll want to think about upgrading to the official Capricorn PTFE Tubing with Pneumatic Fittings & Tube Cutter from Amazon.

Change Your Nozzle

Sometimes a good option is to just change to another nozzle that you either have spare, or to purchase a quick one. Nozzles are really cheap to get if you want a single one, but I’d recommend getting yourself a set of nozzles.

One that would work really great is the LUTER 10Pcs Nozzle Set from Amazon.

It includes 5 stainless steel nozzle cleaning needles, 1 curved tweezer, 1 straight tweezer, 1 socket wrench to help remove and install your nozzle, a flat wrench, as well as a transparent box to put it package these items.

This set is a fairly modern creation that plenty of 3D printer users are finding really helpful, so I’d definitely get this for yourself.

Purchase a New Heater Block

If the methods above don’t work, you might not have to purchase a whole new hotend, rather simply purchase a new heater block from Amazon and simply replace that one part.

I’d recommend the MakerHawk 5Pcs Aluminum Heater Block from Amazon.

It even has thermistors that come with it in case yours gets damaged, which isn’t too uncommon.

It’s a good idea to even have some spare heater blocks for when an issue like this happens in the future because it means you can quickly replace things and get printing again.

You want to make sure that your heater block doesn’t screw too far into the heatbreak because there won’t be enough space left to screw your nozzle all the way in.

When you look at how the heat break and nozzle screw in, they actually go inside the heater block, so keep this in mind.

Should the Nozzle on My 3D Printer be Flush?

The nozzle on your 3D printer doesn’t have to be flush with the heat block, it should be flush with the threaded heat-break. It is normal for your 3D printer nozzle not to be right up against the heat block. When reassembling your hotend, a small gap between the nozzle and heat block is normal.

If the heat-break is flush with the heat block, it might not be able to be tightened as much as it needs to be.

The ideal way to install a new hotend on your 3D printer is to screw it in all the way, then unscrew it around half a turn, then insert the heat-break. This is so you know that after tightening it, it’s definitely against the heat-break.

This is only when reassembling the hotend, so if you have used it successfully before, you should be able to screw the nozzle in and not worry whether there is a gap or not, either way is fine.

For safety reasons, some people recommend heating your nozzle, then turning off your 3D printer before removing it. If you aren’t careful and end up touching the heater wires with your tools, you can short the mainboard of your machine.

You just have to be ready to take off the nozzle straight away so it doesn’t cool down too much.

How to Fix a Stripped 3D Printer Nozzle on Ender 3 & More

A stripped nozzle on your 3D printer should be replaced. To remove a stripped nozzle, you should use a socket wrench, vice grips, or pliers to get a good grip and unscrew it off. Make sure to remove the nozzle when it’s hot, but do keep safety in mind. An Ender 3 nozzle (M6) takes a 6mm wrench.

I hear that most nozzles get stripped by using  a thin, stainless steel wrench since the brass nozzle is soft compared to the stainless steel material. As shown above, I’d recommend getting a set of nozzles along with the correct-sized socket wrench.

You can get the LUTER 10Pcs Nozzle Set from Amazon which comes with the wrench, as well as 10 nozzles, cleaning needles and tweezers.

Vise grip pliers, as well as another clamping type of tool can work well to get your stripped nozzle removed. Make sure you have another tool that can hold the heater block in place so it doesn’t move around while turning the nozzle.

I’d recommend going for something like the IRWIN Vise Grip Straight-Jaw Pliers from Amazon.

You could also simply use an adjustable wrench like the 6-Inch Craftsman Adjustable Wrench from Amazon.

Some people have even recommended using a blow torch on a low heat on the aluminum block, as long as your electricals are removed, and you have it in held in a vice.

This sounds a lot more intrusive, so you’re probably better off just going with a new heater block rather than going through that hassle.

If you want an informative video about changing your nozzles or Bowden PTFE tubes, you can watch the YouTube video below by Tom from the Tomb of 3D Printed Horrors.

He has a great illustration of each part that makes up the whole hotend, so you have a better idea of what you’ll be doing.

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