Can A Thermos Go Bad?

Thermoses bottles have been popular for years, and rightfully so! They are the best way any traveler can keep their hot and cold beverages at the right temperature for longer, and many people use them daily. Unfortunately, like all other worldly things, thermoses also have a lifespan. Can a thermos go bad?

Generally, a thermos bottle has anti-impact, anti-leakage, and anti-failing characteristics and service life of three to five years. However, during the lifespan of your thermos, anything could happen that shortens its lifespan. Quality, sealing, and air leakage can cause a thermos to go bad.

In the life of your favorite thermos bottle, it may suddenly appear that its insulation may have become damaged, causing your hot drinks to become cold and your cold beverages to become hot. Let’s delve deeper into how a thermos bottle can go bad, and some critical signs you should look out for!

Signs Your Thermos Has Gone Bad

Stainless steel thermoses can last a very long time due to their excellent durability and quality. However, these bottles could still experience some damage throughout their lifetime, and there are several signs you need to look out for when they need to be replaced.

Below are some signs when your thermos has gone bad:

Your Thermos Has Lots Of Dents

Your thermos might have gone bad due to the damage caused by constant dents. Dents will not only affect the overall look of your thermos, but they could damage its inner wall, which is responsible for maintaining the temperature of your beverages.

If you notice this has been the case with your thermos, you can check the silicone valve and seal or replace it if needed.

However, if the insulation of your thermos is damaged, you may need to purchase a new one.

Your Thermos Sweat On The Outside

Typically, a thermos will not sweat due to its double-layered wall. However, if sweating or condensation on the outside of your thermos bottle usually happens, your thermos is not in its ideal condition.

If your water seems to taste and smell like metal, you need to replace your thermos, no matter if you regularly clean or sanitize it.

If the metallic taste does not originate from the tap water, then your thermos is damaged.

Sometimes, your thermos may also leak, which is a clear indication that your thermos has surpassed its lifetime.

Can You Repair A Damaged Thermos?

Although there is no way you can repair a thermos bottle if the problem lies with the insulation, you can still use it.

Because the vacuum state is damaged by the air leakage of the bottle’s body, you can still drink out of your thermos.

However, your thermos won’t be able to keep beverages hot or cold for a sufficient time, but it’s still in a good enough condition. The reason why most thermoses go bad is due to their sealing or air leakage.

When you suspect that the sealing of your thermos may not be good, you can check whether there is a gap in its lid. If the lid is not thoroughly closed, the temperature in your thermos bottle will drop quickly.

If you are sure this is the problem, you can repair it by purchasing another lid with another seal.

If the problem is leakage inside your thermos’s body, there could be something wrong with the bottle’s material.

Small holes can appear in the inner liner of your thermos bottle, which will accelerate the heat transfer between the two vacuum walls of the bottle, which means heat and cold will be lost much faster.

If this is the case, you will not be able to repair your thermos bottle and will be better off purchasing a new one.

How Can You Make Your Thermos Last Longer?

While your thermos can last for several years, a big part of its durability will involve how you take care of it. Let’s discuss some of the ways you can look after your thermos and make sure you get the most out of its lifespan:

Clean Your Thermos Properly And Regularly

Some thermos bottle manufacturers can be concrete when it comes to explaining how to clean their items.

Some instructions state that the thermos is dishwasher safe, while others say that you should only wash them by hand.

This is why it is of utmost importance that you always take care to read the instructions before washing your thermos.

Cleaning your thermos incorrectly could cause significant damage, shortening its durability and lifespan.

Allow Your Thermos To Dry Thoroughly

After washing your thermos bottle, you must let it dry thoroughly in a well-ventilated area. If you immediately place them back in your kitchen cabinet or storage box, it could cause the perfect environment for bacteria, mold, or mildew.

Not allowing your thermos bottle to dry completely could also cause foul smells to seep into your water or beverages.

If you do not have time for your thermos bottle to dry completely, you can take a clean and dry cloth and dry it off by hand.

Never Place Your Thermos In The Freezer

Many people are under the impression that placing their thermos bottles in the freezer will help keep their drinks cold for longer.

However, this is not true, as you should never put a thermos bottle in the freezer, as it could contract and expand due to the melting and freezing of water.

The more expansion and contraction happen, the more damage it could cause to the inner lining of your thermos.

Your thermos could even become cracked and dented without you dropping it because of the constant temperature changes.

Do Not Drop Your Thermos Bottle

One of the most common ways you can damage your thermos bottle is to repeatedly let it fall on hard surfaces. Although a stainless steel thermos may not break as easily as a glass thermos, it could crack and have dents over time.

It could be challenging to be cautious wherever you go, and accidents happen. However, by wrapping a towel around your thermos, you will avoid condensation coming in contact with your hands while keeping your thermos safe and sound!


A thermos bottle could last up to 12 years if you practice the proper care and use. Thermos bottles will outlive any other bottles, as they are naturally made of durable materials and are non-corrosive.

Cleaning and maintaining your thermos bottle correctly will help it last longer and get you the most value for your money!


Similar Posts