Are Thermos Dishwasher Safe? Lets Find Out

Are Thermos Dishwashers SafeThermos products like flasks, food jars, water bottles, cups, mugs, and others play a very important role in everyday life.

From storing food to keeping food and beverages hot, cool and fresh, thermos products have made people’s lives better.

By keeping food safe, thermos products have enabled people to take their favorite food anywhere they go without worrying that their food will spoil.


Is Thermos Dishwasher Safe?

Although thermos products have proved to be important in our lives, the question of whether they are dishwasher safe remains inconsistent.

In this guide, we will look at whether we can clean our thermos product using a dishwasher and the effects dishwashers have on thermos products.

Without further delay, let us disentangle this dilemma of washing thermos products.


Are Thermos Dishwashers Safe

Which thermos products are dishwasher safe?

Thermos products range from food jars, cups, beverage bottles, water bottles, lunch boxes, flasks, and other storage containers. Thermos products use stainless steel vacuum-insulated technology to keep food hot or cool and fresh throughout the day.

Most thermos products are said to be top-rack dishwasher safe. However, their manufacturers recommend handwashing.

Thermos products are delicate and require extra care, besides the extreme heat conditions in the dishwasher and the detergents used by the dishwashers can damage the impressive finishing of the thermos.

This is the reason why all thermos products are top-rack dishwasher safer.

If you place your thermos product at the bottom rack with other utensils, you risk breaking it or spoiling the exterior finishing because of the spinning and extreme heat conditions in the bottom rack of the dishwasher.

For vacuum-insulated mugs and tumblers, the manufacturer says that they are top-rack dishwasher safe. On their care page, they state that;

“This product is top-rack dishwasher safe; however, hand washing is recommended as the dishwasher uses harsher detergents and hot water that may affect the appearance of your product.”

Other products like vacuum-insulated glassware and glass-lined thermos flasks are marked not dishwasher safe. On the manufacturer’s care page, they state that;

“Hand wash only – this product is not dishwasher safe.”

Using a dishwasher to clean some of the thermos products can shorten the lifespan of their insulation mechanism. Furthermore, it can cause water to enter the space between the inner and the outer layer of the product.

How To Clean Thermos Products

Thermos products, unlike other utensils such as plates and cups, have several components that make up their body.

Such components include gaskets, lids, plungers, stoppers, and containers.

Thorough washing is required to ensure that your thermos product is clean and safe for storing your food. So, how do we ensure that we wash our thermos products well?

I understand using a dishwasher to clean our utensils has become the most convenient way to clean in many homes today.

But are all utensils dishwasher safe? Dishwashers clean by spraying hot water first, then spraying hot water mixed with detergents, and finally, rinsing the utensils with clean water.

There is an option of drying the utensil by heating the dishwasher compartments to drain the water.

Most thermos products are top-rack dishwasher safe. However, there are some risks involved when you use a dishwasher to wash your thermos product. This is the reason why most manufacturers prefer handwashing thermos products.

If you are using a dishwasher to wash your thermos product, then this is how you do it.

First, remove the lid of your product and empty any food remainder. Place your thermos product components separately on the top rack, then wash them.

Let your thermos product dry completely. If you are hand washing your thermos product, then use warm soapy water to clean and rinse thoroughly and let it dry before your next use.


Do not use harsh detergents, brushes, or scrubbing pads to wash the interior of the container or the exterior of your thermos product since they may remove the excellent finish that the product has.

Furthermore, avoid using bleaching detergents on any parts of your thermos product, even if it has any discoloration.

Do not submerge or soak in water for elongated periods.

Discoloration can be removed using hot water with denture tablets that are soaked overnight and cleaned with warm soapy water.

Also, you can fill your thermos product with warm water and a teaspoon of soda bicarbonate. Leave it overnight, then wash it in the morning with warm soapy water and rinse it thoroughly.

This way, you will remove any tough stain on your thermos product without scrubbing it.

In cases of residual foods, liquids, or other contents that are trapped between product components, such as lid parts, container parts, and gaskets, then you can disassemble and clean individual parts of the thermos product using either hands or the top rack of the dishwasher.

Final Verdict

Most of the thermos products are said to be safe when placed on the top rack of the dishwasher.

Hand washing is recommended to ensure that all the parts of the container are cleaned properly and that no residual water or food contents are trapped within the container.

If you prefer using a dishwasher for all your thermos products, then you need to check the official website of your thermos product manufacturer to ascertain whether your thermos product is dishwasher safe.

In some cases, you will need to hand wash to ensure thorough cleaning and safety of your product.

Furthermore, if you always use a dishwasher to clean your thermos product, you will have to at least hand wash your thermos product once in a while to get rid of trapped food remains and water.

To ensure your thermos product is safe, it’s better to hand wash so that you can avoid exposure to any risk associated with dishwashers, like extreme heat, breaking, or damaging the exterior decoration of your thermos product.


Frequently Asked Questions

Are thermos products dishwasher safe?

Some of the thermos products are top-rack dishwasher safe; however, the manufacturer recommends handwashing for the best and safe cleaning. Others are only hand-washed to avoid damage and reduction of lifespan.

Why can’t I clean my thermos product using a dishwasher?

For those thermos products that are marked hand washing only, it is dangerous to use a dishwasher to clean. This can damage the insulation mechanism rendering your thermos product not able to keep your food fresh or cool, or hot.

Handwashing will ensure that you handle it with care and clean all the parts thoroughly. Furthermore, the spinning of the dishwasher can break the glassware used.

How do I clean my thermos product?

All thermos products have clear instructions on how to clean them in the care and user guide that come with the product, or you can find the instructions on the manufacturer’s website.

Regardless, hand washing is the best way of cleaning all thermos products.

Wash all parts of your thermos product with warm soapy water, then rinse thoroughly and give time to dry well before you use.

Do not submerge your thermos product in water for an elongated period. Water may enter the spaces between the inside and the outside of your thermos product.

Can I clean my thermos mug/tumbler in a dishwasher?

Yes, a thermos mug/tumbler is dishwasher safe. If you put your thermos mug in the bottom rack of the dishwasher, you risk damaging the vacuum seal. This makes your thermos unable to insulate well.

Irrespective, you will have to disassemble and hand wash once in a while to remove water and food residues trapped inside the thermos mug/tumbler components.

Which components of my thermos product are dishwasher safe?

When disassembled, most components of the thermos can be placed, including the top rack part of the dishwasher, such as the lids, stoppers, plungers, and gaskets.

What can happen if I clean my thermos product in the dishwasher?

Some thermos products that are dishwasher safe are placed only on the top rack. This is to avoid extreme heat conditions that may damage their finishing.

If you place a thermos product that is not dishwasher safe, you risk breaking or damaging it.

How can I get rid of the water that is strapped inside my thermos container?

Perhaps your thermos product has got food residue that has been trapped between the product components like lid parts, gaskets, or other container parts; then you will need to strip your thermos product parts.

You can disassemble your thermos product and wash it part separately and, let it dry, then assemble it carefully. Use warm soapy water to clean all the parts, and rinse carefully with clean water.

To assemble your thermos product properly, check the care and user guide that comes with the product.

How do I remove discoloration inside my thermos product?

If there is discoloration inside your thermos product, you can pour hot water with denture tablets. Let it soak overnight, then clean it with soap and water and rinse thoroughly with clean running water.

Also, you can use lemon juice to eliminate smells. Do not use bleach, abrasive soaps, brushes, or scrubbing pads to clean the inside of the container.

Do not clean using cleaners that have bleach properties.

Are there alternative ways to clean my thermos product?

Apart from using a dishwasher to clean your thermos product, you can hand wash. Handwashing is the best way to clean any thermos product. It will enable you to clean all the parts thoroughly and handle them with care avoiding the risk of damaging or breaking.