Braun ThermoScan Er3 Error — Fix Guide

What it means

Er3 means the ambient (room) temperature is outside the Braun ThermoScan's operating range of 10–40°C (50–104°F).
The thermometer's infrared sensor requires a stable, moderate ambient temperature to calibrate correctly.
Move to a room within this range and wait a few minutes before taking a reading.

Affected Models

Braun ThermoScan 5 IRT6500
Braun ThermoScan 6 IRT6515
Braun ThermoScan 7 IRT6520
Braun ThermoScan 7 IRT6525
Braun No Touch + Forehead

How to Fix It

Move to a room with a normal indoor temperature

Find a room with an ambient temperature between 15°C and 30°C (59°F–86°F) for the most reliable results.
Avoid using the ThermoScan outdoors, in an unheated garage, in a very hot kitchen, or near an air conditioning vent blowing cold air.
Allow the thermometer to stabilise

Once in a suitable room, wait 5 minutes for the thermometer's internal sensor to adjust to the ambient temperature before taking a reading.
Keep the thermometer away from drafts and direct sunlight

Drafts from open windows or air conditioning, and direct sunlight on the thermometer body, can create a localised temperature around the thermometer that is outside the normal range even in an otherwise comfortable room.

Frequently Asked Questions

Is Er3 different from Er1 and Er2?

Yes.
Er1 and Er2 are about the probe tip being too warm or too cold.
Er3 is about the surrounding room temperature being outside the safe range for the infrared sensor to function correctly.
Er3 is the least common of the three.