The part(s) or condition(s) listed below for the symptom String trimmer string line won't feed are ordered from most likely to least likely to occur. Check or test each item, starting with the items at the top of the page.
Try removing the trimmer head and cleaning it thoroughly. If the trimmer head is worn out, replace it.
The trimmer line might be the wrong size. If the trimmer line is too thick or too thin for the trimmer head, the trimmer line won’t feed. Make sure you are using the correct trimmer line for your string trimmer.
The trimmer housing might be cracked, chipped or broken. Inspect the trimmer housing for damage. If the trimmer housing is damaged, replace the trimmer head.