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How often to clean (almost) every appliance in your home

When's the last time you cleaned your dishwasher, fridge or air conditioner? Some scary bacteria may be lurking inside.
Image: Cleaning the oven
Splatters of food on your stove that aren’t promptly cleaned up can become a breeding ground for microbes.kirstyokeeffe / Getty Images/iStockphoto

Spring cleaning season is in serious effect: By now you’ve more than likely spring cleaned like a pro, Kondo-ed your drawers and closets, and ditched all your unwanted stuff. But when was the last time you cleaned out your fridge? Yeah, we haven’t gotten to that yet, either.

“People blow off cleaning appliances because they don’t have the time, or it takes too long to clean the grime that’s built up because they didn’t have the time,” says Becky Rapinchuk, a cleaning expert who goes by Clean Mama, and author of the books Simply Clean and The Organically Clean Home.

To help get us back on track, we’ve rounded up a few experts (including a microbiologist!) to remind us which germs and bacteria can build up on or in common everyday appliances (if we don’t get cracking), explain how often we should be cleaning them, and tell us what to use when we do.


Philip Tierno Jr., Ph.D, clinical professor of microbiology and pathology at NYU School of Medicine, says germs, most often mold fungi and some harmless “environmental bugs” tend to accumulate along the seal of a dishwasher. To stave them off, wipe the seal down weekly with a mild bleach solution (1-part bleach, 9-parts water). Melissa Maker, host of the YouTube channel “Clean My Space,” says the outside of your dishwasher should be wiped down on the outside each time you wipe down the cabinets — once a week. As far as the inside goes: “Replace the filter and put a cup of baking soda on the top rack of the dishwasher and leave it overnight, this will absorb any odors. The next morning put about a cup of vinegar into the bottom of the dishwasher and run it on the hottest cycle,” she says.

Washing Machines

Studies have shown that fecal germs, like E. coli and other intestinal bacteria, and some viruses (including the rotavirus, noroviruses and hepatitis A) can survive in washing machines especially if a bleach or germicide is not used with the wash, says Tierno. To keep such unsavory bacteria at bay, he recommends running an empty cycle with just water and a cup of bleach weekly, or bi-weekly, depending on how often you use the machine. Newer washing machines have a germicidal cycle, which is also effective, says Tierno.


Generally, dryers provide high heat but may not get hot enough to kill germs that cling to your clothes, warns Tierno. The cleaner the washer, the less bacteria you’ll transmit to your dryer. Some newer dryers have a germicidal cycle, which is well worth running weekly to keep them clean.

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“These devices can harbor water-borne Legionella bacteria (as in Legionnaire’s Disease), which can be present in potable water. Unlike most bacteria, they can survive in plain tap water for as long as 140 days to a year and can even survive in hot water at temperatures of 150 degrees Fahrenheit,” says Tierno. To keep your humidifier clean, use a brush and soapy bleach solution to gently scrub it out once a week.

Air Conditioners

Tierno says AC’s are great at controlling particulates in air — like dust mites and fungal spores — as well as a variety of other allergens and particles. “Besides cooling, the removal or reduction of allergens is the main task of an AC system. Therefore, it is imperative to change filters when they become clogged, as well as use the appropriate type filter,” he recommends. Otherwise, wipe down the surface of it with an antibacterial wipe once in a while. Also, Tierno says it’s super important to clean up any water that collects in or around your air conditioner before fungal mold builds up, which can really be a problem for those who are immunosuppressed or have allergies.


“Stoves tend to be somewhat neglected. Splatters or spills of food that aren’t promptly cleaned up can become a good medium for the growth of microbes,” says Tierno. Yuck! To prevent microbes, Maker says stovetops should be cleaned after each use by wiping them down with an all-purpose cleaner and a microfiber cloth. Wipe the front of the unit down once a week. “The inside of the oven should be cleaned every 3 months, or when you notice burnt on food or smoke when you are baking,” says Maker. “Most ovens are self-cleaning, just make sure you remove the racks and clean those separately and follow the manufacturer’s directions for best cleaning practices.”

Microwave ovens

Tierno says, in terms of germs, the biggest problem with your microwave is the door handle. Grab an antibacterial wipe and sanitize the outside every time you put food in it — the kitchen is a hotbed of cross-contamination any time you make a meal. “One must clean the oven chamber with soap and water periodically (dependent upon usage), especially if there are splashes, and also because there are many ‘cold’ spots that don’t reach high temps that can kill germs,” says Tierno.

Another way to clean the inside: In her blog, Rapinchuk recommends cutting up one lemon and placing it in four cups of water in a small glass microwavable bowl. Run it until the water boils, 3-5 minutes, allowing the steam to loosen the grease, drips and grime. Use a sponge or microfiber cloth to wipe the inside clean.


Like it or not, your fridge should be wiped down and sanitized at least once a week, for it is a hotbed of germs. Tierno says raw meats, veggies, eggs and cheeses, and cold cuts, soft cheeses, pate, coleslaw and hot dogs can harbor listeria, which actually thrives at refrigeration temps and is dangerous for elderly, immunosuppressed people and pregnant women. Plus, it is a humid space where fungal mold grows. Wipe up spills on the spot (and the handle, if appropriate) with antibacterial wipes, and give the outside a good wipe-down with whatever the manufacturer says is safe to use on the exterior.

Before you know it, you’ll have a kitchen clean enough to eat off of — as well as eat in.


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