Can a thermos go in the dishwasher (+3 takeaways)

In this blog post, we will answer “Can a thermos go in the dishwasher?” 

Thermoses are one of the most useful things in our homes to keep the stuff hot or cold for a longer time. But when it comes to washing them, one question pops up in our mind.

Can a thermos go in the dishwasher?

If the answer is “yes” but still it is preferable to wash them by hand. Now, the question is why should we avoid using the dishwasher to wash the thermoses, and what will happen if we wash them in the dishwasher?

There are a number of brands, selling a wide range of thermoses in different sizes, shapes, and quality. Mainly, there are two types.

  1. Thermoses that can go in the dishwasher
  2. Thermoses that can’t go in the dishwasher

Thermoses that can go in the dishwasher:

Thermoses that are considered dishwasher friendly are Stainless steel vacuum insulated flasks. They are top-rack dishwasher safe. However, it is suggested to wash them by hand.

If you are still willing to wash it in the dishwasher, then keep it in the top-reck of your dishwasher. Keeping your thermos in the top-rack of the dishwasher will not harm your thermos and your thermos will be clean and will return the way you were expecting.

However, if you keep your thermos in the bottom rack of your dishwasher, it is most likely that your thermos will get damaged and will lose its durability. Keeping the thermos in the bottom rack of your dishwasher can harm the vacuum seal of your thermos and it will not insulate properly.

The other elements, which can shorten the lifespan of your thermos are heat and detergent used in the dishwasher. Your thermos can get damaged and will not insulate properly. 

If you want to keep your thermos for a longer time, without losing its beauty and durability. It is suggested to wash it by hand.

Many brands are giving guarantees that their thermoses are strong enough to keep their durability and beauty alive, even if you wash them in the dishwasher, but the only condition is to keep it on the top-rack of your dishwasher.

However, there are many other brands, who refuse to take this guarantee and suggest washing the thermoses by hand rather than washing them in the dishwasher.

Before you go to any brand to buy your thermos, always keep a check on their manuals, since it is the right way to make a wise choice.

A thermos that can’t go in the dishwasher

Glassware vacuum insulated thermos is not dishwasher friendly. It is highly suggested to wash glassware vacuum insulated thermos by hand to keep them for a longer time. 

Keeping your glassware vacuum insulated thermos at the bottom rack will damage your thermos entirely. The heating element attached at the bottom of your dishwasher and the detergents used for washing in the dishwasher can damage your thermos.

A wide range of insulated thermoses use lead to seal off their vacuum, this could be the main cause of the mold and will damage your thermos, due to the high heating element at the bottom-rack of your dishwasher.

Another thing, which is important to mention here is that washing the thermos more often in a dishwasher will faint the color coating of your thermos.

The lid is dishwasher friendly

The lids of thermoses are dishwasher friendly. Putting them in the top rack will not harm them and you can see them back as you were expecting. However, keeping safety in mind, put the lid of your thermos in the top rack. 

Keeping the lid of the thermos at the bottom rack can damage it too. Since it is seen that lids are more often made up of plastic and rubber parts and keeping them at the bottom rack can cause mold to the lid.

Dishwasher and Rubber gaskets

Have you ever thought of washing out rubber gaskets in a dishwasher? The dishwasher does not play its part when it comes to washing rubber gaskets. Rubber gaskets are the prime places for a mold to build up and dishwashers can’t clean it. You need to wash them by hand. What you can do is just remove it from the lid and give it a good scrub on a wet towel or cloth.


In this article, we answered, “Can a thermos go in the dishwasher”.


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