Getting rid of sewage smell from washing machine

Q: When we use our washing machine, a GE top-loader that we bought in 2015, there is a terrible sewage smell. It’s not inside the machine, but in the basement air. We have tried several ways to fix the problem, including snaking the vents on the roof, replacing the one-way valve into the sink drain and sealing off the pipe into the septic system with foam insulation. But the smell persists. Any suggestions?

A: The solution may have more to do with how you care for your washer than with your plumbing.

Both top- and front-loading machines can develop smells when soap scum, mineral deposits and grime build up on surfaces that stay damp for a long time, creating an ideal environment for mildew and bacteria. Sewer smells, or “egg smells,” are more likely when most washes are done with cool water, because that isn’t as efficient as hot water in rinsing away soap scum, which is food for the bacteria that cause the smells. Periodically running a hot-water cycle can reduce the chances of having a problem, but once smells develop, thorough cleaning is the solution.

GE recommends using hot, soapy water and a soft cloth to clean the door and, on front-loaders, the gasket around the door. If there is stubborn buildup, it suggests using white vinegar and an old toothbrush, never harsh chemicals or steel wool. And get into all the folds of the gasket. Use a swab, an old toothbrush or other tool to remove gunk at the bottom of the gasket, so it doesn’t block the drain holes on the inside bottom edge of the seal.

Residue will also probably build up on soap and softener dispensers, so clean those, too. The fabric softener dispenser on some GE top-loaders is on top of the agitator. After lifting it out, separate the dispenser cup from the cover by grasping the top and pushing down on the cup. Instructions should be in the manual, which can typically be found on a manufacturer’s website. For GE, go to the “owner support” page of geappliances.com, then click “appliance manuals” and enter your model number.

To clean a detergent dispenser, soak it in warm water and scrub with an old toothbrush. For a softener dispenser, GE recommends soaking it in a solution of ¼ cup heavy-duty liquid detergent, one cup bleach and one gallon warm water.

To clean the drum and parts you cannot see or reach, GE recommends using a washing-machine cleaner, such as Cerama Bryte washer cleaner ($8.60 for a 16-ounce bottle from geapplianceparts.com). Washing-machine cleaners are formulated to remove mineral deposits, so they are acidic. As an alternative, GE suggests cleaning the washer with ingredients you might already have. Into the soap dispenser, pour a mixture of ¼ cup water and ¼ cup baking soda, and into the empty washing machine, pour two cups of white vinegar. Then run a hot wash cycle.

People with front-loaders have one other place to clean: a compartment at the base of the machine where water collects around a filter that protects the pump. The combination of stagnant water, lint and grime trapped by the filter can lead to an unpleasant smell, especially if fresh laundry water hasn’t been pushed through the filter recently. Check the manual for how to clean this. Some Samsung models, for example, have a filter door on the front of the machine about an inch from the floor. Inside is a short hose with a plug at the end that pulls out. Once the plug is removed, the hose drains the stagnant, smelly water. Then a bigger plug can be twisted and pulled out, revealing the filter, which can be washed off.

If smells persist even after thorough cleaning, check one more area before calling a professional. The drain pipe or standpipe that the hose empties into might be partially plugged. Remove and rinse the hose. (Check YouTube for how-to videos. There’s one from the repairclinic.com channel titled “GE Top-Load Washer Drain Hose Replacement.”) And try pouring a combination of white vinegar and baking soda down the standpipe. You might also try disassembling and cleaning the P-trap below the standpipe.

If none of this works, it’s time to call an appliance repair company that works on GE washers. And if that doesn’t work, call a plumber.

Once you find and fix the problem that’s leading to the smells, minimize the chances of experiencing a repeat. Avoid using more detergent than recommended, cut back on fabric softeners and occasionally run a wash cycle on hot. You should also leave the washer door open for at least 20 minutes after the last load of the day, so the interior can dry out.