- HVAC
- Smart thermostats
LED-ERROR-TRIANGULO
tado Receiver LED-ERROR-TRIANGULO: lost sensor radio link
Risk level
Medium
Proceed carefully and stop if the check is unclear.
Urgency
Medium
Quick answer
When the triangle error LED on the tado° Wireless Receiver lights up or blinks with the connection LED, the receiver has lost its radio link to the temperature sensor or thermostat; check Settings > Rooms & Devices or hold the top main button for 10 seconds to restart it.
Safety first
Stop and check this first
- The tado° Wireless Receiver is wired to mains power and boiler control terminals: never open the receiver housing or touch internal wiring yourself; any terminal inspection must be performed by a qualified installer with mains power isolated.
- When restarting the Wireless Receiver, hold the main button on the top edge rather than the front Wi-Fi button, and remember it can take up to 30 minutes for the triangle error LED to clear after a sensor restarts.
Safe checks you can perform
- Check which device is offline under Settings > Rooms & Devices in the tado° app
- Verify upright Internet Bridge placement and a minimum 2 to 3 meter separation
- Restart the Wireless Receiver by holding the top main button for 10 seconds
Leave these tasks to a qualified professional
- Do not attempt this professional task: Contact tado° support for radio link diagnostics if the error LED remains active
- Do not attempt this professional task: Book a qualified heating installer if the Wireless Receiver has no power or manual relay output
What a technician must be able to justify
Technician visit
These are the steps they must carry out and show you. Tick them as they work: if steps are skipped, do not accept a part swap.
These are not instructions for opening or handling the equipment yourself. They are the checks that should support a technical conclusion.
Contact tado° support for radio link diagnostics if the error LED remains active
What they dotado° technical support checks the radio link quality between your Internet Bridge, Wireless Receiver, and temperature sensor.
They must show youthe exact blinking pattern of the 3 front LEDs (heating, connection arrows, and error triangle) and the online status under Settings > Rooms & Devices.
In writingthe support ticket reference, the serial numbers of your Wireless Receiver and temperature sensor, and the radio link diagnosis or warranty replacement decision.
Book a qualified heating installer if the Wireless Receiver has no power or manual relay output
What they doA professional heating engineer inspects the mains power supply and boiler control terminals if the Wireless Receiver shows no LEDs or fails to fire the boiler in manual mode.
They must show youa manual heating test using the top main button with the heating LED lit, plus a safe power supply check after isolating the circuit at the fuse box.
In writingthe installer's written service report covering the Wireless Receiver power supply and boiler relay wiring.
Before accepting a part or repair
Nothing has been shown yet. Do not accept a part swap based on the code alone.
Follow these steps
Note: Follow the documented order. An error code identifies the affected system, but it does not prove by itself which part has failed.
Check which device is offline under Settings > Rooms & Devices in the tado° app
- Who:
- you, checking the tado° mobile app.
- How:
- open the tado° app and go to Settings > Rooms & Devices to see whether the Wireless Receiver, Wireless Temperature Sensor, or Smart Thermostat shows offline; if you just restarted the sensor, wait up to 30 minutes for the error LED to turn off.
- Result that matters:
- identify whether a single room sensor or the entire Internet Bridge radio link is disconnected.
- If the sensor reconnects and the triangle error LED turns off within 30 minutes:
- radio communication is restored.
- If devices remain offline or keep blinking after 30 minutes:
- check the Internet Bridge placement in the next step.
- Evidence to keep:
- screenshot of Settings > Rooms & Devices and a short video of the Wireless Receiver LEDs.
Evidence: The Wireless Receiver lost the radio link to the Wireless Temperature Sensor or Smart Thermostat. How can I fix this?
Verify upright Internet Bridge placement and a minimum 2 to 3 meter separation
- Who:
- you, inspecting the Internet Bridge and room sensor positions.
- How:
- make sure all 3 LEDs on the Internet Bridge are solid, place the Internet Bridge upright, and keep at least 2 to 3 meters of distance between the Bridge, the Wireless Receiver, and the Wireless Temperature Sensor.
- Result that matters:
- eliminate close-range radio saturation and restore the link to the Internet Bridge.
- If the connection LED (three arrows) blinks once at regular intervals and the triangle LED turns off:
- link restored.
- If the error LED and connection LED continue blinking simultaneously:
- proceed to restart the Wireless Receiver.
- Evidence to keep:
- photo of the upright Internet Bridge placement and its 3 status LEDs.
Evidence: The Wireless Receiver lost the radio link to the Wireless Temperature Sensor or Smart Thermostat. How can I fix this? · What do the LEDs and blinking states on the Wireless Receiver mean?
Restart the Wireless Receiver by holding the top main button for 10 seconds
- Who:
- you, pressing only the external main button on the top edge of the Wireless Receiver.
- How:
- press and hold the main button on the top edge of the Wireless Receiver (not the Wi-Fi button on the front) for about 10 seconds until the LEDs turn off and blink again; if no temperature reading arrives for over 30 minutes, press that top main button to toggle heating manually.
- Result that matters:
- reboot the Wireless Receiver radio module and enable manual heating control while troubleshooting.
- If the triangle error LED turns off within 30 minutes and the app shows the receiver online:
- issue resolved.
- If the triangle error LED stays lit or keeps blinking past 30 minutes:
- contact tado° support.
- Evidence to keep:
- timestamp of the 10-second restart and the LED state 30 minutes later.
Evidence: The Wireless Receiver lost the radio link to the Wireless Temperature Sensor or Smart Thermostat. How can I fix this? · What do the LEDs and blinking states on the Wireless Receiver mean?
Still not solved
If the error persists, stop here. See what the technician must do and show you.
Where this code applies
A code is meaningful only inside the right product and version context.
Primary scope
- System
- HVAC
- Brand
- tado°
- Product type
- Smart thermostats
Known code variants
- LED de error del Receptor Inalámbrico
- LED de error y LED de conexión parpadean simultáneamente
- Símbolo de triángulo con exclamación Receptor Inalámbrico
- tado Wireless Receiver warning triangle
- The error LED and the connection LED blink simultaneously
- Triangle exclamation symbol Wireless Receiver
- Triángulo de advertencia Receptor Inalámbrico tado
- Wireless Receiver error LED
What it means
In tado°'s official support guides for Wireless Receiver LEDs, symbols, and lost radio links (covering the EU Wireless Receiver and UK Programmer with Hot Water Control, while the older Extension Kit uses one top LED), the front face includes a triangle exclamation error LED. When the error LED and connection LED blink together, the receiver cannot reach at least one temperature sensor; if solid, it signals a device fault. This LED state alone never proves that the Wireless Receiver or boiler is defective: it usually reflects a radio drop, low sensor batteries, or a recent sensor restart (taking up to 30 minutes to clear).
Warnings and stop conditions
- Higheditorial warning
The tado° Wireless Receiver is wired to mains power and boiler control terminals: never open the receiver housing or touch internal wiring yourself; any terminal inspection must be performed by a qualified installer with mains power isolated.
Evidence: The Wireless Receiver lost the radio link to the Wireless Temperature Sensor or Smart Thermostat. How can I fix this? · What do the LEDs and blinking states on the Wireless Receiver mean?
- Loweditorial warning
When restarting the Wireless Receiver, hold the main button on the top edge rather than the front Wi-Fi button, and remember it can take up to 30 minutes for the triangle error LED to clear after a sensor restarts.
Evidence: The Wireless Receiver lost the radio link to the Wireless Temperature Sensor or Smart Thermostat. How can I fix this?
Symptoms and causes
Probable causes · in order
- Lost radio link to the Wireless Temperature Sensor or Smart ThermostatCommon
The Wireless Receiver has not received temperature readings from the paired Wireless Temperature Sensor or Smart Thermostat for over 30 minutes, causing the error LED and connection LED to blink together.
Evidence: The Wireless Receiver lost the radio link to the Wireless Temperature Sensor or Smart Thermostat. How can I fix this? · What do the LEDs and blinking states on the Wireless Receiver mean?
- Up to 30-minute resynchronization delay after restarting a measuring deviceCommon
tado° notes that after you restart a Wireless Temperature Sensor or Smart Thermostat, it can take up to 30 minutes before the triangle error LED on the Wireless Receiver turns off.
Evidence: The Wireless Receiver lost the radio link to the Wireless Temperature Sensor or Smart Thermostat. How can I fix this?
- Internet Bridge placement or close-range radio interference under 2 to 3 metersPossible
If the Internet Bridge is powered off, lying flat, or placed closer than 2 to 3 meters to the Wireless Receiver or Wireless Temperature Sensor, radio communication can fail.
Evidence: The Wireless Receiver lost the radio link to the Wireless Temperature Sensor or Smart Thermostat. How can I fix this?
- Temporary Wireless Receiver lockup keeping the triangle error LED litLess common
A temporary fault state in the Wireless Receiver can leave the triangle error LED illuminated until you restart the receiver using the main button on its top edge.
Evidence: The Wireless Receiver lost the radio link to the Wireless Temperature Sensor or Smart Thermostat. How can I fix this? · What do the LEDs and blinking states on the Wireless Receiver mean?
Virtual technician
Does LED-ERROR-TRIANGULO still appear after these checks?
Answer a few questions to narrow down the likely cause and the safest next action. Guidance only - it never replaces a professional.
Sources and technical references
- 3
What do the LEDs and blinking states on the Wireless Receiver mean?
tado° · 2026 · official_doc
- 4
¿Qué significan las luces LED y su parpadeo en el Receptor Inalámbrico?
tado° · 2026 · official_doc
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