Automatic Watch Running Fast? Five Causes, Starting With Magnetism

An automatic watch that gains a few seconds a day is normal. One that suddenly gains minutes is telling you something. In most cases the cause is simple, and often it is fixed in a few minutes. Here are the five usual suspects, in the order I would check them.

First, what counts as "fast"?

A mechanical watch is not a quartz watch. Depending on the movement and how it was regulated, a few seconds to around ten seconds a day either way is normal. Our Elemental, for example, is regulated to within ±12 seconds a day. If yours is in that range, nothing is wrong. If it is gaining minutes a day, read on.

1. Magnetism (the most common cause by far)

Inside the movement, a hairspring only a few hundredths of a millimetre thick controls the timekeeping. If it becomes magnetised, its coils stick together, it effectively gets shorter, and the watch races ahead, often by minutes a day.

Modern life is full of magnets: phone cases and their clasps, laptop speakers, tablet covers, handbag catches, induction cooktops, even the clasp on some bags. Leaving a watch next to any of them overnight is enough.

How to test it: hold a simple compass near the watch and move it slowly around the case. If the needle twitches, the watch is magnetised.

How to fix it: a watchmaker demagnetises a watch in seconds, often for free or a small fee. You can also buy an inexpensive demagnetiser. Once fixed, the watch usually returns to its normal rate straight away.

2. A knock or a drop

A hard shock can shift the hairspring or knock the regulation slightly. If the watch started running fast right after a fall or a sharp knock, this is the likely cause. It needs a watchmaker to check and regulate it.

3. How you leave it at night

A mechanical watch runs at slightly different rates depending on its position: dial up, dial down, crown up or crown down. This is called positional variance. You can use it to your advantage: if your watch runs a little fast, try leaving it overnight in a different position, for example crown down, and check it the next morning. Many owners correct a few seconds a day this way, for free.

4. Temperature

Big temperature changes affect the metals in the balance and the oil in the movement. A watch left in a hot car or worn in very cold conditions can run differently from usual. This is normally temporary.

5. It is due for a service

After several years the oils in the movement thicken and dry. A watch that slowly drifts out of its usual rate, gaining or losing, is often simply asking for a service. Most automatic watches need one every five to seven years.

What not to do

• Don't open the caseback yourself. You risk dust inside and losing the water resistance.
• Don't try to correct the rate by pushing the hands forward or back every day. Fix the cause instead.

The short version

A few seconds a day: normal. Minutes a day: check for magnetism first with a compass, then think about any recent knock. If neither explains it, take it to a watchmaker for regulation or a service.

Related: automatic watch losing time or stopping overnight and how to wind and set an automatic watch.