Before working through the steps below, it helps to know which thread is actually snapping - this narrows down where to focus and saves time.

• Note which thread is snapping - looper, left needle, right needle or centre needle
• If you're finding it difficult to tell, try threading each path in a different colour - this makes it immediately obvious which thread is breaking when you run the machine

This fixes the majority of thread breaking problems. Remove all threads completely and start again - don't just re-thread the thread that broke, as the problem is often elsewhere in the threading path.

• Raise the presser foot before re-threading so the tension discs open properly
• Always thread the looper before the needles
• Go slowly and refer to your manual rather than going from memory - even one missed guide can cause repeated breaking

If any thread is catching or snagging on its way to the machine it will break under the tension of cover stitching even if everything else is set up correctly.

• Make sure each spool is sitting correctly and unwinding smoothly
• Check the thread isn't catching, tangling or wrapping around the spool holder
• If your machine has a retractable thread stand, make sure it's fully extended
• Use the correct spool cap for each thread size
• For nylon, rayon or metallic threads, try using a spool net to help the thread unwind evenly

Tension that's too tight is a common cause of thread breaking on a cover stitch machine.

• Reset all tension dials to the default or middle setting and test on scrap fabric
• Adjust gradually from there rather than making large changes - small adjustments make a big difference
• Focus adjustments on the thread path you identified in step 1

Poor quality or old thread breaks easily, particularly at the higher speeds a cover stitch machine runs at.

• Use good quality thread suited to cover stitching - we highly recommend Madeira Aerolock, which is specifically designed for overlockers and cover stitch machines and runs beautifully at speed
• Avoid using very old thread that may have degraded over time - thread that has been sitting on the spool for years loses its strength and flexibility

A bent, blunt or incorrectly fitted needle can cause the needle thread to break repeatedly.

• Replace with a fresh needle of the correct type - the ELx705 is recommended for most cover stitch machines
• Make sure it's fully inserted with the flat side to the back and tightened securely
• If you can't remember when you last changed the needle, it's overdue

A rough spot anywhere along the thread path can shred thread repeatedly, even if everything else is set up correctly.

• Run your finger carefully along each thread path and feel for any rough spots on guides or the needle plate
• Pay particular attention to the looper tip - a damaged looper tip is a common cause of repeated thread shredding
• If you find damage to a looper, get in touch and we can advise on replacement parts

Once you've worked through the steps, test on scrap fabric of a similar weight to your project. Run a decent length of stitching and confirm all threads are holding without breaking before returning to your work.