How to Maintain a Cordless String Trimmer and Blower Combo?

Keeping your cordless string trimmer and blower combo running like new doesn’t require a toolbox full of specialty gear. Most of the work is preventative—a few minutes of attention after each session prevents the slow buildup of grass, dust, and wear that kills these tools before their time. The routine below covers the specific steps for your combo unit, plus model-specific details for the most common DEWALT and Greenworks kits on the market, so you can keep your equipment running from the first spring cutting to the last fall clean-up.

The Golden Rule: Remove The Battery First

Before you touch the cutting head, clean a vent, or inspect the string, the battery must come out. This is the single most important safety step, and every cordless trimmer manual emphasizes it. Removing the battery eliminates any chance of a surprise start, protecting your fingers from the spinning line and the blower’s fan.

Even a quick jam-clearing job isn’t worth the risk. Pop the battery out, set it aside, and then work on the tool. That habit also protects the tool itself—working on the trimmer head while the motor is live can bend the drive shaft or damage the gear assembly if something binds.

Cleaning And Care: After Every Use

The fastest way to shorten a cordless trimmer’s life is to let caked-on grass and dust accumulate. After each session, take a minute to clear the vents and air intakes on both the trimmer and the blower; clogged vents restrict airflow and overwork the motor. Keep the handles clean, dry, and free of oil or grease, and clear any obstructions from the blower nozzle, as a blocked airflow path cuts performance dramatically.

When the housings need more than a wipe, use mild soap and a damp cloth. Avoid solvents, harsh chemicals, abrasive cleaners, and water on the tool body—these can damage plastic housings and electrical components. Most manuals note that the power tool has no additional lubrication or maintenance and contains no user-serviceable parts, so a simple wipe-down is all the routine care these machines require.

Trimmer Line: The Right Size, Installed Correctly

Replacing worn trimmer line is the most frequent maintenance task, and most problems come down to using the wrong diameter or installing the spool incorrectly. Use the exact line diameter recommended in your model’s manual; one common spec is 0.065 inches, while many mid-size trimmers use 0.080-inch line.

Before replacing the line, remove the battery. Then inspect the spool for tangles or jams—a line that’s broken, worn, empty, or incorrectly installed needs prompt attention. Winding the line onto the spool with even tension and matching the directional arrows on the spool and trimmer head prevents most feed issues. Here’s a quick reference for popular combo kits:

Battery care is equally critical—store batteries in a cool, dry place away from direct sunlight, and avoid leaving them fully discharged for long periods. When you’re ready to upgrade or replace an aging kit, our tested roundup of the best cordless string trimmer and blower combos covers the top performers across price points.

Storage And Common Mistakes To Avoid

Store the tool, charger, and batteries in a dry, secure location out of reach of children, away from moisture and temperature extremes. The most common mistakes that shorten a combo unit’s life are entirely avoidable: cleaning without removing the battery, using water or harsh solvents on plastic housings, installing the wrong line diameter, ignoring vent blockages, and storing batteries discharged in hot, sunny sheds.

One final point: maintenance specifics are always model-specific. Shared battery platforms mean , but always consult your owner’s manual or DEWALT’s official product page before replacing parts or buying new batteries—the right check costs two minutes and prevents an expensive mismatch.