Washing machine carbon brushes (also called motor brushes) are small carbon blocks that deliver electrical current to the motor’s rotating armature via the commutator. In brushed motors (common in many older and mid-range washers), they wear down over time due to constant friction—typically lasting 5–10 years depending on usage. When broken, worn, chipped, or no longer making proper contact, they cause distinct symptoms. Recognizing these early prevents motor damage or complete failure.
The most common and obvious sign is the drum failing to turn. The machine fills with water normally, agitates weakly or not at all, sits idle during wash/spin cycles, then drains—leaving clothes soaking wet. This happens because the motor receives insufficient or no power when brushes lose contact.
Intermittent or weak motor operation is another key indicator. The drum may turn slowly, stutter, jerk, or run “half-heartedly” before stopping. You might hear the motor hum or struggle without full rotation, especially during high-load phases like spin.
Unusual noises frequently accompany brush failure. A spluttering, fizzing, crackling, or arcing sound often occurs as electricity jumps gaps between worn brushes and the commutator. Ticking or buzzing under load points to arcing. In severe cases, a faint electrical burning smell or wisps of smoke emerge from the motor area—caused by overheating or carbon dust buildup.
Visible sparking is a strong warning. Sparks may flash from under the machine (near motor brushes) or inside near the commutator, especially noticeable in dark conditions or through vents. Excessive sparking creates carbon dust/soot around the motor, blackening holders and worsening contact.
Burning smell or overheating often follows prolonged arcing. The motor runs hot, may trip thermal protectors, or blow fuses/RCDs if severe. After replacement, improper seating can cause similar fizzing/burning—always check alignment.
Less common but related signs include:
- Excessive vibration if one brush wears faster, causing imbalance.
- Machine stopping mid-cycle with error codes (on digital models) related to motor faults.
- Reduced spin speed or failure to reach full RPM.
These symptoms usually affect only the motor-driven functions (agitation/spin); fill, drain, and electronics often work fine, isolating the issue to brushes rather than pump, inlet valve, or control board.
Broken brushes rarely happen suddenly—gradual wear produces progressive symptoms. Early mild sparking or weak performance escalates to total non-rotation.
Diagnosis tips: Unplug machine, access motor (rear panel usually), remove brushes (spring-loaded in holders), measure length (replace if under ~1 cm), check for chipping/burning, inspect commutator for grooves/uneven wear (should be even chocolate-brown). Clean dust, ensure free brush movement.
Replacement is straightforward DIY for many models (Bosch, Zanussi, Beko common), costing little. Use correct compatible brushes—wrong ones cause poor contact, arcing, or damage.
Ignoring symptoms risks commutator scoring, motor burnout, or fire hazard from sustained arcing. Prompt attention saves costly repairs
