Braun No touch + forehead thermometer screen: dashes, 0 – 2 cm, colours and errors
Braun’s instruction manual for the No touch + forehead thermometer (BNT 400) names every state below. Each one has Braun’s own words in quotation marks, what Braun says to do, and a link to our page on the same symbol across other makes.
Check your thermometer’s manual — makers differ.
All 13 Braun No touch + forehead screen states at a glance
| On the screen | What Braun’s manual says it means |
|---|---|
--- | Ready to measure |
Moving dashed line | Measuring now |
0 – 2 cm | Too far from the forehead |
Green, yellow or red light with the reading | Braun’s fever colour for the age group selected |
Yellow backlight with all 3 age icons flashing | You are setting a preferred age range |
Food & bath icon with a blue backlight | Food and bath mode, not a body temperature |
Silent-mode icon | Beeps are switched off |
Flashing battery symbol | About 20% battery left; it still measures |
Steady battery icon, nothing else | Batteries empty; it cannot measure |
Out-of-range message (drawn as a picture in the manual) | The reading or the room is outside the working range |
Self-check display flashing without stopping | System error |
Blank display | No power |
°C or °F | The temperature scale, set by a switch |
Which models this covers
The manual read here is Braun Healthcare’s Asia-Pacific edition of the BNT 400. Other Braun no-touch models have their own manuals, and their screens may differ; Braun’s US site answered an earlier request (2026-09-29) with a bot check, so its US editions were not read.
Each state, in Braun’s words
--- Ready to measure
“When the thermometer is ready and on or 2.5 cm (1 inch) away from the forehead a horizontal line of dashes (“---”) will appear on the screen.”
“Three dashed lines mean the thermometer is ready to take temperature.”
What Braun says to do: “Press the temperature button.”
The dashes are the ready screen, not a failed reading.
Every make: Flashing °C, °F or mode symbol. Source: Braun No touch + forehead thermometer BNT 400 — instruction manual (Asia-Pacific, PDF) Checked 2026-10-13.
Moving dashed line Measuring now
“The display will show a dashed line animation while it takes a reading. Once the reading is complete a confirmation beep will be heard and the appropriate fever light color will be displayed on screen.”
Braun asks you to hold the thermometer and the forehead steady while the animation runs, because movement changes the reading.
Source: Braun No touch + forehead thermometer BNT 400 — instruction manual (Asia-Pacific, PDF) Checked 2026-10-13.
0 – 2 cm Too far from the forehead
“If the device is positioned too far away from the forehead, it will prompt you to move closer by displaying the characters “0 – 2 cm”.”
What Braun says to do: “Slowly move the device toward the forehead until the dashed line animation starts and a reading is displayed.”
“0 – 2 cm” is a distance instruction, not a temperature or an error number.
Every make: POS, ERP or Er 2. Source: Braun No touch + forehead thermometer BNT 400 — instruction manual (Asia-Pacific, PDF) Checked 2026-10-13.
Green, yellow or red light with the reading Braun’s fever colour for the age group selected
“If temperature is in the normal range, a long beep will sound when the measurement is complete. If the temperature is in the fever range, 10 short beeps will sound to indicate the measurement is complete.”
| Age range | Green: normal temperature | Yellow: moderate fever | Red: high fever |
|---|---|---|---|
| 0–3 months | ≥35.8 – ≤37.4 °C (≥96.4 – ≤99.4 °F) | — | >37.4 °C (>99.4 °F) |
| 3–36 months | ≥35.4 – ≤37.6 °C (≥95.7 – ≤99.6 °F) | >37.6 – ≤38.5 °C (>99.6 – ≤101.3 °F) | >38.5 °C (>101.3 °F) |
| 36 months – adult | ≥35.4 – ≤37.7 °C (≥95.7 – ≤99.9 °F) | >37.7 – ≤39.4 °C (>99.9 – ≤103.0 °F) | >39.4 °C (>103.0 °F) |
Braun defines 0 months as a gestational age of at least 37 weeks at birth. Ten short beeps instead of one long beep mean the reading is in Braun’s fever range for the age group selected.
Every make: Fever colours and fever symbol. Source: Braun No touch + forehead thermometer BNT 400 — instruction manual (Asia-Pacific, PDF) Checked 2026-10-13.
Yellow backlight with all 3 age icons flashing You are setting a preferred age range
“The unit will turn on, displaying a yellow backlight and the 3 age range icons will flash.”
“Once the desired age range is selected, stop pressing the button and wait 3 seconds. The green backlight will illuminate, and the selected age range will turn solid.”
You get here by holding the power button and the AgeSmart button together for 4 seconds. Braun’s way to remove a preferred age range is to take the batteries out, wait 30 seconds and put them back.
Source: Braun No touch + forehead thermometer BNT 400 — instruction manual (Asia-Pacific, PDF) Checked 2026-10-13.
Food & bath icon with a blue backlight Food and bath mode, not a body temperature
“Press and release the food & bath temperature mode button.”
“the screen backlight will turn blue and three dashes will show on the screen indicating the thermometer is ready to take a temperature.”
In this mode Braun says to aim up to 6 cm (2.5 inches) from the water or food, never touching it.
Every make: Body, forehead, object or room mode symbol. Source: Braun No touch + forehead thermometer BNT 400 — instruction manual (Asia-Pacific, PDF) Checked 2026-10-13.
Silent-mode icon Beeps are switched off
“To activate the silence feature, slide the switch to the silent mode position and take a temperature reading. An icon will appear on the screen to indicate that the thermometer is in silent mode.”
With sound off you will not hear the 10 short fever beeps, so read the backlight colour instead.
Source: Braun No touch + forehead thermometer BNT 400 — instruction manual (Asia-Pacific, PDF) Checked 2026-10-13.
Flashing battery symbol About 20% battery left; it still measures
“When 20% of battery life is left, the display flashes the low battery warning symbol; however, the device can still work until the battery life has 0% left.”
What Braun says to do: “Replace batteries.”
The BNT 400 takes 2 AAA batteries, according to the manual.
Every make: Low battery symbol. Source: Braun No touch + forehead thermometer BNT 400 — instruction manual (Asia-Pacific, PDF) Checked 2026-10-13.
Steady battery icon, nothing else Batteries empty; it cannot measure
“If the steady battery icon is the only symbol shown on the display, the device cannot work. The battery should be replaced immediately.”
What Braun says to do: “Replace batteries.”
On this model a flashing battery still measures and a steady battery does not, which is easy to get the wrong way round.
Every make: Low battery symbol. Source: Braun No touch + forehead thermometer BNT 400 — instruction manual (Asia-Pacific, PDF) Checked 2026-10-13.
Out-of-range message (drawn as a picture in the manual) The reading or the room is outside the working range
“This message displays when the measured temperature is lower than 34 °C (93.2 °F) or higher than 43 °C (109.4 °F) or when the room temperature is outside the operating range of 15 °C – 40 °C (59 °F – 104 °F).”
What Braun says to do: “Re-measure the temperature, carefully following the instructions in “How to use” section.”
One message covers three causes on this model: a reading too low, a reading too high, or a room that is too cold or too warm.
Every make: Hi on a thermometer. Source: Braun No touch + forehead thermometer BNT 400 — instruction manual (Asia-Pacific, PDF) Checked 2026-10-13.
Self-check display flashing without stopping System error
“System error – self-check display flashes continuously and will not be followed by the ready beep and the ready symbol.”
What Braun says to do: “Wait 1 minute until the thermometer turns off automatically, then turn on again.”
If it keeps happening, Braun’s next step is to reset it by removing the batteries and putting them back in, and after that to contact customer service.
Every make: Err or Er with a number. Source: Braun No touch + forehead thermometer BNT 400 — instruction manual (Asia-Pacific, PDF) Checked 2026-10-13.
Blank display No power
“Blank display. Thermometer does not have power.”
What Braun says to do: “Please check if the batteries have been loaded correctly. Also check polarity (<+> and <–>) of batteries.”
Braun’s last step, if it still does not work, is to contact customer service.
Source: Braun No touch + forehead thermometer BNT 400 — instruction manual (Asia-Pacific, PDF) Checked 2026-10-13.
°C or °F The temperature scale, set by a switch
“°C / °F switch is accessible in the battery compartment.”
“Slide switch to °C or °F to set preferred temperature scale.”
There is no button sequence for the scale on this model: the batteries have to come out to reach the switch.
Every make: °C or °F on the display. Source: Braun No touch + forehead thermometer BNT 400 — instruction manual (Asia-Pacific, PDF) Checked 2026-10-13.
These pages report what each maker’s manual says and quote it wherever health is involved. They do not diagnose anything, they are not medical advice, and they do not tell you whether a temperature is a fever or what to do about it; only your own thermometer’s manual and your doctor or nurse can do that for the person you are looking after.
Other thermometer makers
Sources
Every state above is quoted from this document on Braun’s own website, fetched and read on the date shown. Words in quotation marks are Braun’s; everything else is ours.
- Braun: Braun No touch + forehead thermometer BNT 400 — instruction manual (Asia-Pacific, PDF) Checked 2026-10-13.