Due the danger and complexity of electronic equipment repair, the following technical tip is intended for professional reference only. Please refer to manufacturer’s recommendations as Encompass does not guarantee the accuracy, reliability or safety of this information.
What most people describe as a rotten egg smell is caused by hydrogen sulfide gas. This gas is commonly found in sewers and is caused by bacteria metabolism.
If the smell of hydrogen sulfide is coming from the washing machine, the likely culprit is a buildup of mold, grime, mildew or old soap within the washing machine or a component like the door gasket. Thankfully, getting rid of this awful smell is incredibly easy since most of the time a good, thorough cleaning is all that’s needed.
Following are common causes of washer smells and fixes. Please note that the first two refer to front-loader washing machines; for top-loader washing machines, skip to #3.
#1 – Something Stuck in Door Seal (Front Loader Only)
Front-loader washing machines have a large rubber door seal (sometimes called a bellow or gasket) that goes around the inside of the door. The seal is intended to prevent water from spilling out of the washing machine during a cycle.
Sometimes a small piece of clothing, like a sock, can get stuck inside the gasket, and over time it will get covered in mildew. If left for a long time, this can start to smell like rotten eggs.
To make sure the door seal doesn’t have anything stuck in it, you simply need to:
- Pull door seal back, look inside for any loose clothing items and remove.
- Thoroughly clean door gasket with a sponge and hot, soapy water.
- After cleaning, leave the door open to dry and air out.
Cleaning Tip: Manufacturers recommend users keep the door open on front-loader washing machines after completing cycles to enable the unit to dry out. This can help prevent mildew and mold from developing.
#2 – Clogged Drain Plug or Pump (Front Loader only)
Another possible cause of smell is a clogged drain plug. In most models, there is a drain plug at the bottom of the washing machine on either the front, sides, or back of the appliance.
To check the drain plug and filter:
- Locate drain plug and remove cover plate if one is there.
- After accessing drain plug, turn cap off. Some water might leak out, so have a towel nearby.
- Once plug is removed, reach in and remove drain filter.
- Clean areas around drain plug and filter with hot soapy water.
- Pour a glass of hot water mixed with a couple drops of white vinegar into the washing machine drum; the water should then drain out through the hose, bringing out any grime in the hose.
- Once these components have been cleaned, reinstall them in the unit. If the rotten egg smell is still apparent, run the machine on a cleaning cycle and check the sewer (see reason 4 below).
#3 – Washing Machine is Dirty (Top Loader)
The best way to remove smell from a washer is to give it a good clean. This helps prevent mold, grime and mildew from building up, resulting in a terrible smell.
How to clean a washing machine:
- Open washing machine door.
- Set washer to hottest setting and largest load capacity.
- Once water starts to fill up, add one quart of bleach (about 4 cups).
- Once washer is full of water, close lid and set it to a long spin cycle. When the cycle ends, leave the washing machine for about one hour before turning back on and completing a standard wash cycle.
- When the wash cycle ends, turn it to the hottest setting and largest capacity again. When it’s filling up, add 3 cups of white vinegar and a ½ cup of baking soda.
- When the washer is full, close lid and turn set to a long spin cycle again. When the spin cycle ends, open lid and wipe out washing machine with a clean cloth.
- Leave the washing machine lid open, and let it dry out for a couple of hours before using it again. If your washing machine still smells bad, try checking the sewer (#4).
Reason 4 – Sewer Clogged
If cleaning did not rid the washer of the rotten egg smell, it’s possible the sewer or drain is clogged. When this happens, the smell can go through the drain hose and into the machine.
Here’s how to solve this problem:
- Locate where the drain hose is connected – most likely it’s connected to a standpipe connected to sink.
- Remove hose from standpipe, and see if a smell is coming from it.
- If it’s smelly, start by giving the whole area around the standpipe a good clean with hot, soapy water.
- The smell could also be due to a faulty p-trap allowing sewer gas to come up through the drain hose and into the washing machine. To solve this problem, pour a bucket of hot, soapy water down the standpipe. If the smell goes away, the p-trap was the source. Sometimes after pouring hot water down the drain, the p-trap will start working again, and sometimes it will need to be replaced. If the smell comes back, a plumber may need to replace the p-trap.
Special thanks to Fred’s Appliance Academy for this helpful tip.