Dishwasher smells, causes and cures

Bad smells from a dishwasher, care and maintenance tips

A smelly dishwasher can cause intense aggravation and can have a negative impact on your entire kitchen.  People do not expect a cleaning appliance to be the source of a bad odor and are often caught unawares in such a situation. It is important to remember that the simple care and maintenance of your dishwasher is the most effective deterrent against bad smells.


The root cause for the development of bad odors from a dishwasher is neglect. Most people simply don’t take the time to remove excess food from serving dishes and plates or rinsing them before placing in the dishwasher. Inevitably this leads to bits of food getting trapped in the corners of your washing appliance where they may remain over an extended length of time. Along with these food deposits, grease residue can also accrue within the nooks and corners of your dishwasher. From this point, it is just a matter of time before bacterial growth starts to develop around these festering food particles. The chemical reaction produced when bacteria acts on trapped food particles and grease is responsible for the release of gases. The bad smell from your dishwasher is essentially a physical indication that such gases are being produced. This bad odor is easily transferable, and can easily be passed on to all dishes that are being washed in your appliance.

Maintaining your dishwasher

 The pre wash might not have always been considered to be an indispensable part of the cleaning cycle. However, it is advisable to remove leftover food from your dishes before you place them in the dishwasher. Rinsing dishes before putting them in a dishwasher is a sensible practice that prevents unnecessary build ups of food residue.

Make routine manual checks of the dishwasher seal and drainage area. Typically, food particles tend to get trapped near these locations. If left unattended over a lengthy duration of time, these trapped food particles will emit a foul odor. You can get rid of these blockages with a mixture of detergent and watered down bleach. (Dilute one teaspoon of bleach with 1 quart of water.)

An improperly installed dishwasher hose can also cause problems that may result in the formation of bad smells. If the hose does not allow smooth drainage, residual water may start building up inside your machine. If you do not use your dishwasher regularly, this water can stagnate and release a foul odor. Always make sure that the hose is hung at an appropriate angle to ensure the complete drainage of water from your washing appliance.

A bad odor might also develop if an external object comes into direct contact with the heating element of the dishwasher. If a plastic item makes contact with the washer's heating components, you are likely to detect the inevitable burnt plastic odor.

The warmth provided by the dishwasher insulation can attract the attention of common household pests such as mice. They may choose to nest within the insulation. The smell caused by mice feces and urine is quite strong and unpleasant. Sometimes, these pests may even get trapped and perish within the insulation. Over time, the decomposing bodies emit an extremely foul odor. The only option here is to replace the areas of insulation that have been affected.

Regular use of gel based detergents is not recommended. These products generally contain excessive bleach, which can cause wear and tear of the rubber seals found inside most dishwashers.

Make sure you methodically clean your dishwasher every couple of months. This will ensure that food deposits, grime, and grease build ups are kept in check. While cleaning, pay special attention to areas such as the dishwasher seal, the sprayer arm ports, as well as the filter. These are the areas that display the maximum potential for developing bacterial build ups. Regular cleaning can severely inhibit the possibility of bad odors from a dishwasher.

If you are not in the habit of running the drying cycle of your dishwasher, it is recommended that you leave the appliance door open following the final wash cycle. This allows any standing water to evaporate and ensures that the dishwasher is completely dry. Water trapped within the dishwasher for a period of time has the tendency to develop an odor comparable to that of split milk.

Learning how to clean a dishwasher

Learning how to clean a dishwasher the right way can help eliminate the problems of bad odor.

Dip a small brush or toothbrush into a mix of hot water and liquid detergent. Using this brush you can start scrubbing the insides of the dishwasher. Do not neglect the insides of the door, and pay special attention to any gaps and folds around the rubber seal. Quite often, you will find fairly significant deposits hidden near the lower extremities of the door and the hinges. Also pay close attention to the cleaning of the screen (filter) located at the base of the dishwasher tub. This is an area that can have the maximum concentrations of food deposits and needs to be cleaned thoroughly. Likewise, care should be taken to clean the ports that are visible on the sprayer arm.  (In case of stubborn dirt build ups you may need to use a slightly abrasive cleaner.) Once you have scrubbed loose most of the deposits, you can use a hot soapy sponge to wipe away this grime. If you are having a hard time cleaning the seal with regular detergent, you can use a mixture of baking soda and vinegar. Dip your brush into this mix before scrubbing the area vigorously.

Make sure you thoroughly cleanse all the hard to reach corners inside your dish cleaning appliance. Extracting the lowest rack will help expose the drain area. Check the drain to make sure there are no large deposits present that can block it, or cause damage to the dishes or the pump. You can now wipe down the interior of the dishwasher with a clean damp cloth or sponge to remove any lingering traces of detergent.

Fill a dishwasher-safe cup with white vinegar and place it on the top shelf. Run a cycle using the warmest water setting possible. This will help eliminate any bacteria, grease, grime, or food deposits, and will neutralize any unwanted odors present in the dishwasher. If you lack access to vinegar, you may choose to use baking soda instead.

Tips for dealing with a smelly dishwasher

Most dishwasher-specific detergents deliver their optimal performance at higher temperatures (usually 130 degrees and above). At these temperatures the detergent completely dissolves and delivers maximum sanitization. Therefore, you should select the maximum water temperature setting on your dishwasher for proper removal of any hard set deposits.

After cleaning out the dishwasher filter make a solution comprising of 1 quart water, a quarter cup chlorine bleach, and 2 tablespoons of liquid detergent. Wash the insides of the dishwasher thoroughly with this mixture including the gaskets, shelves, and the walls. If this does not produce the required results, repeat the procedure using a solution of baking soda and water. The mildly abrasive quality of the baking soda will help dislodge any tough deposits and counteract any bad odors that may be present. Finally, let the dishwasher run empty at the maximum water temperature.

A simple method of eliminating odors is to add a few lemon peels to your dishwasher during the wash cycle. The citrus oils present in the peel neutralize unpleasant odors and adds a natural lemon fragrance to your dishes. Alternatively, you may choose to place a cup of natural (non-sweet) lemonade in the top rack of your dishwasher and then run a complete wash cycle.

If you are having only limited success cleaning your dishwasher with commercial detergents, you may use a combination of white vinegar and baking soda. First, clear the dishwasher of food particles stuck to the filter. Then, drench the insides of the appliance with white vinegar. Allow this to rest for 30 minutes before scrubbing with a sponge or cloth that has been dipped in vinegar. You may dust some baking soda over the sponge to enhance the cleaning effect. Finally, wipe away any residual t

Disclaimer: The information provided has been prepared as a guide only and the steps taken are likely to vary for different appliance models. We strongly recommend using a qualified engineer to undertake major repairs and fault finding.


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