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The Encyclopedia of Horology

Complication · Display

Service Indicator

Partially verified

A complication that alerts the wearer when the watch is due for professional servicing.

Definition

A complication that alerts the wearer when the watch is due for professional servicing.

Historical origin

Designed to prevent the damage caused by running a watch with dried lubricants.

How it works

Usually a long-duration countdown (e.g., 5 years) driven by a very slow-moving gear train.

May show a color change in a small window.

Pocket watch context

None.

Wristwatch context

A rare feature found in some high-end tool watches or concepts (e.g., Jaeger-LeCoultre Extreme Lab).

Identification

  • A window that turns red after several years of operation

Servicing notes

Resetting the indicator is usually part of the official service procedure.

General guidance only. Complicated mechanisms should be assessed and serviced by a qualified watchmaker or clockmaker specialist, not adjusted at home.

Diagram

12345let downstripcleanoilregulateorder of work; never skip letting down the mainspring
Schematic: order of work at the bench. An outline schematic drawn to show the arrangement of the parts discussed here. It is not a dimensioned working drawing and does not depict a particular maker's calibre.

Sources & references

  1. de Carle, D., Watch and Clock Encyclopedia
  2. Britten, F. J., Old Clocks and Watches and Their Makers
  3. Horological Journal (British Horological Institute), technical articles

Where sources disagree, the disagreement is stated rather than resolved silently.