Why does my dishwasher smell? And how do I get rid of the dishwasher’s bad smell?
The first thing to do is look for built up food residue, whether it is solid chunks of food on the side of the dishwasher, meat pieces clogging the drain cover, nuts stuck in the food grinder (if your dishwasher has one), or gunk stuck in the drain hose. What lines the walls of the dishwasher is easiest to see and remove.
Don’t forget to check the sprayer arms, since piece of vegetables sometimes fall in them and then get stuck in it. Kernels of corn are perfectly sized to do exactly that. Check the drain for the dishwasher, since food can clog both the drain cover and the drain hose. Check the glass guard, if the dishwasher has one, and utensil holder. Sometimes the food rot smell originates from food debris in the bottom of the utensil holder.
If you’re lucky, this is fixed as soon as you clear out or un-kink the drain hose, then run the dishwasher with baking soda in the detergent dispenser. If there was rotting debris in the drain hoses, you may want to run it with several cups of white vinegar and nothing else so that the unit is sanitized, and the vinegar-water mix will clear any clogs in the drains as well any grease lining the drain hose.
If the dishwasher’s bad smell was due to food debris that started to rot, then you can run the dishwasher without any dishes but a handful of baking soda to neutralize the odors. Two cups of vinegar is another alternative. Using both baking soda and vinegar may be necessary for rotted or moldy smells.
The problem can be due to the dispensers themselves. A dishwasher’s rinse agent dispenser stuck shut or residue can start to smell, though this is very different than the rotted food smell most complain about. Cleaning the dispenser and then running the dishwasher with a load of baking soda will remove the rest of the residue. If the soap dispenser is stuck shut, you’ll notice barely cleaned dishes and mildew-soap smells. Whether it is the dish soap dispenser or rinse aid dispenser, either one failing to open when it should might be due to a broken latch, bad software or rusting control mechanisms. You can try running the dishwasher with dish soap simply poured in the bottom of the dishwasher to see if the dishwasher can properly clean the dishes, then run it with several cups of baking soda dropped in the bottom of the unit while the dispensers are open so the baking soda can scour them clean. This is recommended in case it is caked on soap residue that is keeping the dispenser lids stuck shut for part of the cycle.
Sometimes the bad smell in your dishwasher is due to mold. A cracked dishwasher shell that lets water seep into the insulation of the unit can be patched, but this won’t kill the mold or fully eliminate the odor. In these cases you have to replace the dishwasher insulation and shell unless you just want a new dishwasher. If the leak is in the water hoses to the dishwasher or drain hose from the dishwasher, you have to fix the hose connections or replace the leaking hoses, then use bleach and vinegar to kill the mold.
If cleaning all obvious food residue, soap residue and mold from the unit hasn’t eliminated the smell, start checking the dishwasher door seal. Perhaps there is food debris or soap residue stuck in the seal, or a loose seal that lets water seep into the door before mold starts growing. If you are lucky, you’ll fix the problem by cleaning the seal thoroughly. A leaking seal causing moldy smells isn’t solved by gluing the seal back in place, since that doesn’t kill the mold. If you think water has leaked into the dishwasher door and facilitated the growth of mold, you want to call for service since the best solution may be replacing the dishwasher door. The appliance repair person can also see if the water leak bad enough into the door of the dishwasher to cause mold growth has affected the control board or sensors in the dishwasher, too.