Watch Troubleshooting: Common Faults and What Causes Them
Most watch faults are one of four things: not enough power, magnetism, a loose crown, or a service that is overdue. Three of those you can diagnose at your kitchen table in five minutes.
This guide starts with the symptom, because that is what you actually have. Find yours below, work through the checks in order, and you will know whether you have a problem or a workshop visit.
Start with the symptom
| Symptom | Most likely cause | First check |
|---|---|---|
| Stops overnight | Not enough power reserve | Hand-wind it fully and watch for a day |
| Gains minutes a day | Magnetised hairspring | Hold it near a compass |
| Loses time steadily | Service overdue, or low amplitude | Note the loss per day for a week |
| Fogged crystal | Moisture past a failed gasket | Stop wearing it and get it opened |
| Quartz seconds jumping in fours | Battery nearly flat | Replace the battery |
| Crown will not wind | Screw-down crown still locked | Unscrew anticlockwise first |
An automatic that keeps stopping
This is the most common complaint about mechanical watches and it is usually not a fault at all. An automatic is wound by the movement of your arm, and a desk-bound day does not move it much.
Typing, driving and holding a phone are all low-amplitude motions that barely turn the rotor. A watch worn through eight hours of that can end the day with less stored power than it started with.
The test is straightforward. Wind the crown thirty to forty turns, set the time, and leave the watch face up overnight without wearing it.
If it is still running twenty-four hours later, the watch is fine and the problem is your week. If it stops well short of its rated power reserve, it needs attention.
A watch that has suddenly gained minutes
A mechanical watch that goes from a few seconds a day to several minutes has almost certainly been magnetised. The hairspring coils stick to one another, the effective spring gets shorter, and the balance swings faster.
Magnets are everywhere now. Phone cases with magnetic mounts, laptop lids, tablet covers, handbag clasps, headphones and induction hobs are the usual culprits, and none of them feels like a hazard.
To test, hold the watch close to a compass and move it slowly. If the needle swings to follow, the watch is magnetised.
The fix is a demagnetiser, which is a small mains-powered coil costing very little, and the process takes seconds. The National High Magnetic Field Laboratory has a readable explanation of why ferromagnetic materials hold a field in the first place.
Losing time steadily
Steady loss is different from erratic behaviour and usually less urgent. Every mechanical watch has a rate, and a consistent loss of ten seconds a day is within tolerance for many movements.
Before assuming a fault, measure properly. Set the watch against a reliable time source, leave it a week without adjusting, and note the total difference.
Position matters. A watch left crown-up overnight will often run differently from one left dial-up, so if the loss appears only some mornings, try changing where you put it down.
Loss that is getting worse month by month is the signal for a service. That is the movement telling you the lubricant has gone, and continuing to wear it wears the pivots.
Moisture under the crystal
This is the one genuine emergency on the list. Water inside a watch will corrode the movement, and the damage is progressive from the moment it gets in.
Light fogging that clears in warm air still means the seal has failed. The water vapour is inside, and it will condense again.
Stop wearing the watch and get the case opened and dried as soon as possible. A day of delay can be the difference between a gasket replacement and a movement replacement.
The usual causes are a crown left unscrewed, a case back not properly reseated after a battery change, or gaskets that have simply perished with age. The water resistance guide covers why a rating is not permanent.
Quartz faults
A quartz watch whose seconds hand jumps in four-second steps is not broken. That is the end-of-life indicator built into many movements, and it means the battery is nearly flat.
Change it promptly. A battery left to die completely can leak, and the resulting corrosion is often not worth repairing on a modest watch.
A quartz watch that runs but keeps poor time may have a tired battery delivering unstable voltage, or it may have taken a knock. Replace the battery first, because it is cheap and it eliminates a variable.
Have the gaskets replaced whenever the case is opened. A battery change is the most common cause of a watch that was water-resistant last week and is not this week.
Faults that are not faults
Several normal behaviours get reported as problems, and knowing them saves a wasted trip to a watchmaker.
A date that changes at some point other than midnight is usually a watch set twelve hours out. Move the hands round a full twelve hours and it will correct itself.
A slight rattle when you shake an automatic is the rotor spinning on its bearing, which is what it is supposed to do. A grinding noise is not.
A mechanical seconds hand that does not land exactly on the markers is normal too, since the hand is fitted by hand and the beat rate does not divide evenly into the printed track. None of that affects timekeeping, and the movements explainer covers why.
What is worth doing yourself
Some of this list is a five-minute job and some of it is a way to make things worse.
- Do: hand-wind an automatic to test it, demagnetise with a proper demagnetiser, check the crown is screwed down, keep a written note of the daily rate.
- Do not: open the case back without a gasket to hand, put a cased watch in an ultrasonic cleaner, try to regulate the movement with a screwdriver, keep wearing a watch with moisture inside it.
Regulation in particular looks simple and is not. The adjustment is fine, the results are position-dependent, and it is easy to turn a watch that loses ten seconds a day into one that loses forty.
If a fault does not resolve with the checks above, the answer is a service. The movements explainer covers why lubricant degradation eventually catches every mechanical watch, and the care guide covers the intervals that prevent most of this.
Frequently asked questions
Why does my automatic watch keep stopping?
Usually not enough wrist movement to keep the mainspring wound. Wind it thirty to forty turns by hand, then check whether it runs for a full day off the wrist. If it does, the watch is healthy and needs more wear or an occasional manual wind.
Why is my watch suddenly running fast?
Almost always magnetism. A magnetised hairspring sticks to itself and the balance swings faster, which can add minutes a day. Test it against a compass, and have it demagnetised — the process takes seconds.
What should I do if there is condensation in my watch?
Stop wearing it and have the case opened and dried straight away. Moisture inside a watch corrodes the movement continuously, and the difference between a cheap fix and an expensive one is measured in days.
Is it worth repairing an inexpensive watch?
Sometimes not, and an honest watchmaker will tell you. A service can cost more than a modest watch is worth, though a sentimental piece or one with parts availability is usually worth keeping alive.
Work from the symptom, do the cheap checks first, and treat moisture as urgent while treating a steady few seconds a day as normal. That order solves most faults without a workshop.