How to label two nearly identical household devices

Choose an identifier that stays with the device

Two fans of the same model could have tags marked “Fan A” and “Fan B.” Record the last few characters of each serial number in the household record if that information is accessible. If you later replace Fan A, mark the old item as retired so its service history stays attached to the correct device. Room names can change and identical devices can trade places. A distinct tag and a private record of the manufacturer’s identifier can help confirm which unit is which.

Keep events tied to the correct unit

Suppose Fan A was repaired and Fan B was bought later. Record the repair under the Fan A identifier, including the date and source of the service report. If both devices have the same model number, the model describes their type; it does not distinguish their histories.

Handle replacement without overwriting the past

When Fan A leaves, mark its record retired and identify the replacement separately. If you reuse a label for convenience, include the new unit’s distinguishing detail and start date. Otherwise a future reader may attribute an old repair or expired warranty to the replacement.