Modern washing machines, particularly high-efficiency (HE) front-loading models, are designed to be water and energy-efficient, but this design creates an environment where mold and mildew thrive. Tight seals and the use of less water mean that moisture, soap scum, and organic residue often remain trapped inside after a cycle finishes. This warm, damp environment is ideal for microbial growth, which develops into a sticky matrix known as biofilm. Eliminating this buildup requires a comprehensive cleaning process that addresses both the visible mold and the hidden areas where it originates.
Gathering Supplies and Safety Precautions
Gathering the necessary supplies ensures the task can be completed efficiently and safely. You will need rubber gloves, old towels or rags, a small scrub brush or an old toothbrush for tight spaces, and a spray bottle. For cleaning agents, have either liquid chlorine bleach, white distilled vinegar, or a commercial washing machine cleaner.
Safety must be the first consideration when using strong cleaning agents. Ensure the area is well-ventilated by opening windows or turning on an exhaust fan. Chlorine bleach and vinegar must never be mixed, as combining these two substances releases toxic chlorine gas. If you use both agents, run a full, empty rinse cycle between their applications to completely flush out the first chemical before introducing the second.
Deep Cleaning the Washer Drum and Tub
The first step is to sanitize the main interior components, including the drum and the outer tub, by running a maintenance cycle. This process uses high heat and a strong cleaning agent to circulate through the water system, breaking down accumulated biofilm and mold spores. Set the machine to the hottest water temperature available and select the longest wash cycle, such as heavy-duty or tub-clean.
Choose either chlorine bleach or white vinegar, but not both. If using chlorine bleach, add approximately one cup to the detergent dispenser or directly into the drum. If you prefer white vinegar, pour two cups of distilled white vinegar into the detergent dispenser. Allow the machine to run through the entire cycle without interruption.
Once the initial cleaning cycle is complete, run a second, empty rinse-and-spin cycle using only hot water. This second cycle flushes away remaining cleaning solution residue, dead mold spores, and loosened debris. After the final cycle, use a clean, dry towel to wipe down the entire interior of the drum to remove any standing moisture and residue.
Manual Cleaning of Mold-Prone Components
While the deep cleaning cycle addresses the main tub, several components require manual attention because they trap moisture and debris. The rubber door gasket, or boot, on front-loading machines is a common location for mold growth due to its folds and tight seal. Carefully peel back the rubber seal and wipe out the trapped water, lint, and soap scum using a rag soaked in a diluted cleaning solution, reaching deep into all the crevices.
The detergent dispenser drawer is another area where residue from liquid detergents and fabric softeners accumulates, providing a food source for mold. If possible, remove the entire drawer assembly and soak it in hot, soapy water, using a small brush to scrub away sticky buildup. Also clean the housing where the drawer sits, as this area often harbors unseen mold and residue.
The drain pump filter, typically located behind an access panel at the bottom front of the machine, must be checked and cleaned. This filter catches small items, lint, and sludge that can cause water to stagnate and promote mold growth. Before removing the filter, place a shallow container and a towel underneath to catch the draining water. Scrub the filter with a brush under warm running water to clear all debris before securely replacing it.
Preventing Future Mold Growth
Long-term maintenance is necessary to prevent the recurrence of mold, which thrives in dark, moist conditions. The most effective habit is to always leave the washer door ajar after the final load, allowing air to circulate and the drum to dry completely. This simple action prevents the tight seal from trapping the humidity mold needs to grow.
After removing the laundry, take a moment to wipe down the rubber door seal and the glass door with a dry cloth to eliminate any standing water or moisture. Additionally, only use high-efficiency (HE) detergent, which is formulated to rinse out thoroughly in low-water cycles. Using the correct, minimal amount of detergent is also important, as excess suds leave residue that feeds mold growth. Running a maintenance cycle with hot water and a cleaning agent once a month will help keep the internal components free of accumulating biofilm.