Why Does My Sewing Machine Keep Unthreading?

A sewing machine is a unique and time-saving machine that allows sewers to stitch together their fabric in no time and produce an excellent sewing result when functioning properly. However, when there is a slight issue with the sewing machine, sewing can become a nightmare and less enjoyable until you get it fixed.

One of these annoying and unwanted situations is when the thread constantly starts to come out of the machine. No matter how much you try to rethread the machine, it keeps on coming out. This can be frustrating as it slows down your sewing process and can make your project becomes messy. 

In this article, we will be discussing why your sewing machine keeps unthreading, what are the causes, and how it can be fixed so that you can continue your sewing project smoothly without having to rethread the machine every second. 

Why Does My Sewing Machine Keep Unthreading?

There are numerous reasons that can affect your machine resulting in a constant unthreading. However, most of the causes can be easily identified and simply fixed without having to spend a fortune. Some of the causes of the constant unthreading of your sewing machine include.

– Improper Threading

When facing a constant unthreading, it is important to inspect your threading method. Since you have to substitute and switch thread for different purposes during a sewing process, it is possible to have messed up a step during the threading process. To ensure the machine has been properly threaded, you will have to rethread the machine starting from the top spool.

While there are different threading patterns for each sewing machine, you have to be certain that the thread passes through the tension plate and the machine thread guides before running through the front of the needle. You can also make use of the sewing machine’s user manual to follow the proper procedure of threading your machine. 

– Not Raising The Needle Before Starting

It is very vital to ensure that the needle is perfectly elevated before proceeding with the sewing process. While computerized sewing machines have been designed to automatically set the needle’s position, you have to manually do the hand cracking when using a basic sewing machine to position the needle in the perfect spot.

When your needle is not perfectly positioned before you start to sew, your sewing machine can begin to constantly unthread. To prevent this, you have to be mindful of the needle position before working and ensure that it is properly fixed. You can put a note on your sewing machine to promptly remind you to do this if you tend to forget easily.

– Small Thread Tail Length

An excess long trail thread from the needle prevents the thread tail from jumping out of the needle’s eye when you start the sewing machine. When the thread tail is too short, it can easily jump out and can keep on recurring as you attempt to start the sewing machine. This can be easily prevented and solved by leaving an additional inch to the needle’s thread tail.

– Improper Thread Tension Levels

Maintaining a perfect tension on the thread aids the sewing machine in feeding the thread into your fabric. When the tension level is low, it can cause recurrent unthreading. Computerized sewing machines come with an assisted tension control that evaluates the thread to pick a perfect tension level but sometimes you have to do the adjustment manually on your basic sewing machine. 

Inspect the tension adjuster and make sure it is located almost near the middle of the setting as it could have accidentally moved, affecting the machine’s thread tension level. From the middle, you can proceed by moving the tension adjuster up and down to examine if a different thread tension level will stop the sewing machine from unthreading. 

– Wrong Needle and Thread

There are different types and sizes of needles and thread and they all function for different projects. Making use of the wrong needle and thread for a project will affect the sewing machine’s performance and can result in constant unthreading.

Make sure you make use of thicker threads and needles for projects with heavyweight fabrics as a thin thread passed into a large needle to work on a heavyweight fabric will not function properly and can make the machine unthread while sewing. 

– Damaged and Defective Needle

If the thread is not the cause of the unthreading after inspection, then it might be the needle. A damaged needle will commonly shred the sewing thread, but it is also capable of causing unthreading as well. Consistent use can dent a needle and should be replaced immediately, the needle can also get damaged by coming in contact with a solid garment component.

If the machine’s needle is suspected to be the cause of the constant unthreading of the sewing machine, all you have to do is to replace the dent and damaged sewing needle with a new and perfect one to stop the sewing machine from unthreading. 

– Shoddy Thread

There are different types and qualities of thread available for sewing. When an old thread is not properly stored, the thread can suffer some damages which could result in snagging into the sewing machine and fabric when used. You can also experience such with a new thread with sub-standard quality.

When a thread is damaged, it is possible to go unnoticed. You can run a finger along the length of the thread to check for bumps or divots. If you’re uncertain after checking out the thread, thread your machine with another sewing thread to check if it still continues to unthread.

– Not Feeding Fabric Properly

When your fabric is not fed correctly, the fabric begins to move freely underneath the machine’s foot which could result in consistent unthreading. To prevent this from happening, you have to ensure you start your sewing process by gently moving your fabric forward.

– Incorrect Wounding Around the Bobbin

Making use of a new spool of thread that has not been properly wound around the bobbin can also cause your machine to unthread.

To prevent this, you have to make sure you wound the thread correctly when putting in a new spool of thread to ensure a smooth feed through the top and bottom.

– A Mismatch Spool

When the spool of thread doesn’t match the needle size, it can result in unthreading. Making use of a small needle with a large spool will make the thread tangle and causes other problems like recurrent unthreading.

To prevent this from happening you have to make sure the spool of thread you’re about to use for your sewing machine does compliment the needle size. 


Constant unthreading of your sewing machine can be quite annoying. When experiencing this unwanted situation, you have to do a thorough inspection of your sewing machine checking out the above-listed factors.

You can also make use of your sewing machine user manual for details on how to correctly thread the machine, the perfect needle size, and other information that can help to keep your sewing machine in perfect condition.

If the unthreading persists after trying out all these methods, you might want to take your machine for a proper inspection and repair. This process might cost you unless the sewing machine is still under warranty.