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How to Fix Clogged and Leaking Nozzles - Nikko Industries

How to Fix Clogged and Leaking Nozzles

3D printing is a very interesting manufacturing process. However, some problems can frustrate even its best users. Of the many problems associated with the process, clogged and leaking nozzles are the most common.

These two are mutually exclusive and can result into 3D prints of very low quality. The problems are very frustrating, but like any problem out there, we have solutions ready. Don't worry, this article will make you go through the process, solve it, such that you are back printing quality in no time. Let's get right on it.

Causes and Solutions to a Clogged Printhead

A clogged printhead is the most common problem of the two. This is because it is easy for you to do things that can result into it. To understand printhead clogging, you should know the things causing the problem. Below are the factors that result into a clogged printhead and what to do to eliminate such a scenario.

·        Your print environment is dusty

If you have a dusty environment that is prone to small materials that can enter the printhead, you have a chance of having a clogged printhead. The materials (dust/small particles) can decide to rent a place on your filament, reach the hot end and ultimately lead to clogging.


If you have this problem, you need to use the cold pull method to unblock your print head. The process will be explained below for better understanding.

·        You Don't Clean!

Not cleaning is an easy factor that can lead to a clogged printhead. This becomes more pronounced if you use different materials.


If it has occurred, you might need the cold pull method for this. However, to remove or reduce the chance of that happening, you need to clean the printhead after every use.

·        Heat Creep

Heat Creep will occur if you have a 3D printer whose hot end doesn't cool properly. When this occurs, the filaments you are using will become more viscous at the hot end. Therefore, you will need much force to push the filament out. If the 3D printer does not have the required force, you just authorized the filaments to clog your printhead.


The interesting part about heat creep is that the extruder will make noise when heat creep is about to occur. When this occurs, the next thing to do is to stop the printing process and remove the filament. However, before you do that, ensure that the hot end's cooling fan is working and secure the heat sink and heater block.

·        Hot end temperature is too low

Temperature plays a major role in 3D printing, and if it is too low, the filament won't be melted. "Un-melted" filaments are difficult to extrude, which leads to clogging.


The temperature depends on the materials you are using with 3D printing. Therefore, you must be sure of the specs of the filament. Common 3D printing materials such as PLA and ABS have extrusion temperature of about 2000C and 2450C. If you are still having the same problem, increase your temperature by 50-100C. However, be careful not to pass your hot end's temperature.

·        Nozzle too close to the bed

This is something more relatable to beginners in the process. If you are printing and the printhead is on the print bed, where do you want the extruded material to go? There won't be room to eject the filament, and this will clog the printhead.  


Printing with the nozzle being close to the bed is a result of many things. If inexperienced, you should make sure you keep your eyes out for the nozzle position. If it is because of the 3D print bed, make sure you have a properly leveled bed.

·        Inconsistent Filament Diameter

If your filament is not within the standard diameter of the extrusion width, usually 1.75mm or 3mm you will have clogging issues.


If you think this is the cause, you will need to measure the diameter of the filament. A good way to do this is to use a pair of calipers and measure it in random places. If the filaments do not conform to the requirements, you need to get a new brand.

Cold Pull Method

The cold pull method is the right method to remove clogged material from a printhead when you can't trust yourself with power tools. It is safe and efficient and can be used irrespective of the level you are.

Cold pulling works in a different light. Instead of using temperature or chemicals to remove the clogged materials, you reduce the hot end's temp to the glass transition temperature. The glass transition temperature is one in which the filaments will be between the solid and liquid state. Therefore, you will be able to pull the clogged materials out. Cold pulling works well if the filaments you are using are Nylon, ABS, or PLA. Below are the steps to go about the process.

Before you start: Cold pulling is a tricky process if you are using the Bowden tube. Therefore, you should remove it before you start. When you are done, you can put it back in.

·         Step 1

Start the process normally, as you will do in normal printing. Raise the temperature to the printing temperature. Feed about 10cm of filaments into the printer using the hot end. It would help if you made sure that the filaments are straight as possible. You can also use colored filaments since they will make it easy for you to see what you are doing. If you can't get anything through the hot end, you need to use a plier and thin wire to remove the blockage.

·         Step 2

When you start seeing some of the filaments coming out of the printhead, you are ready for step 2. You need to reduce the temperature at the nozzle. This depends on the material/filament you are using. For example, it is 1200C for ABS, 900C for PLA, and 1000-1400 for Nylon. We are trying to make clogged materials hot so that they are malleable but not soft.

·         Step 3

Start pulling the filament till it starts coming out. If the clogged material is coming out easily, you can further reduce the temperature. However, if you are having a problem with removing it, you should increase the temperature.

If you are successful with the process, you should have a smooth and clean filament at the end. When you are sure of the printhead being unclogged, you can put back the Bowden tube and continue printing.

What Causes a Printhead to Leak

Printhead leakage is another frustrating problem that you will surely pray you don't meet. It's caused by a loose heat block assembly. A loose heat block assembly occurs when there is intense vibration during printing. It can also be due to mechanical damage during cleaning.

No matter the cause, a leaking printhead has its heated filaments oozing out uncontrollably. If this continues, you will have a problem with quality since the heated filaments will start dripping into your print.

Interestingly, you might think no gap can lead to the problem. You might think you tightened the nozzle effectively. However, it would help if you remember that 3D printing is all about temperature and a rise in temperature leads to expansion of materials. Therefore, you have something that can continuously lead to the gap presence.

How to Fix a Leaking Nozzle

The next question is how you want to fix the nozzle. Yes, you can get a new heat block assembly if you do which. However, if you are the type who gets the kick from doing something yourself or don't have the cash, you don't need to. Yes, we are saying you have a good chance of fixing this problem.

Solving this problem is all about tightening the heat block. However, the right way to do this is to tighten the block after heating it. This way, you will eliminate the chance of a gap forming during the next heating process.

Fixing a leading nozzle comes in two parts cleaning and assembly, explained below.


You will need to disassemble the heat block and clean it. Cleaning is a recommended process since it will reduce the chance that it will leak later. You should heat the heat block assembly before cleaning for cleaning to be more effective.


You should first fit the parts of the dissembled heat block together in the cool state. It is easier to do, and you can even use your hand. After assembling using your hand, use a plier to hold the assembled parts and heat them. You should then tighten the parts more on heating until you are sure that the filaments won't come out.


Even the best 3D printing enthusiast doesn't like clogged and leaking nozzles. Therefore, you see them fretting about the problem. However, solving the issue does not have to be problematic. While they are undoubtedly annoying, there are easy solutions to them. In order to make things easier, this article discussed the solutions to the problem. Each solution is unique. However, you might need to combine them if the causes are linked together. Learn how to fix clogged and leaking nozzles and watch yourself produce prints of high quality


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