Why does my watch's glass fog up from the inside?

Why is the glass of my watch fogging up from the inside?

If the glass of your watch is fogging up from the inside, there's moisture inside the case. This can have various causes and isn't always an immediate sign of a defect.

When is fogging not a concern?

Slight, short-term fogging can occur when the watch is exposed to a strong change in temperature, for example:

• when you come in from the cold in winter into a warm room
• when moving from a very warm to a cold environment
• in high humidity combined with strong temperature differences

In such cases, the humidity present inside the case can briefly condense on the inside of the glass.

If the fogging disappears completely within a short time and doesn't occur regularly, this is usually not a cause for concern.

When should I have the watch checked?

The following are not normal:

• fogging that persists for a longer period of time
• recurring fogging without a clear change in temperature
• visible drops of water under the glass
• larger accumulations of moisture inside the case
• functional issues with the watch after contact with water

In these cases, moisture may have entered the case.

How can moisture get into the watch?

Possible causes include:

• a crown that isn't fully closed
• aged or damaged seals
• contact with water beyond the specified water resistance
• hot water or steam
• showering or bathing
• soap, shampoo or other cleaning products
• salt water or chlorinated water
• strong changes in temperature

The water resistance of a watch isn't a permanently fixed property, either. Seals can change over time or lose their effectiveness.

What should I do now?

If you notice moisture under the glass:

1. Don't expose the watch to any more water.
2. Don't operate the crown or any pushers, if present.
3. Don't open the case yourself.
4. Don't try to dry the watch with a hairdryer, on a radiator or with any other heat source.

Excessive heat can cause further damage to seals and other components.

Do I need to contact customer service straight away?

If the fogging is very slight and disappears completely within a short time after a strong change in temperature, you can keep an eye on the watch for now.

If the fogging persists, keeps recurring, or you can see drops of water under the glass, please contact our customer service as soon as possible.

Moisture that remains inside the case for a longer period of time can cause corrosion, which can damage the movement or other components.

What information should I give customer service?

So that we can assess your case quickly, please send us the following information, if possible:

• your order number, if available
• the model of your watch
• how long the fogging has been occurring
• whether the watch has previously been in contact with water
• whether the fogging is permanent or only visible from time to time
• a photo that shows the moisture as clearly as possible

We'll then work with you to check whether your watch should be technically inspected.