- Appliances
- Air purifiers
Continuous alert icon
Dyson Continuous alert icon on purifier: LCD alert triangle
Risk level
Low
Usually safe to check without specialist tools.
Urgency
Medium
Quick answer
An alert triangle on the LCD screen of a Dyson purifier means the machine needs attention. If it is a temporary alert icon that disappears on its own, keep using the machine; if the continuous alert icon or an error code stays on, switch off and unplug for 10 seconds.
Safety first
Stop and check this first
- Always switch off and unplug the purifier before checking the filters or brushing away dust, and never use detergents or polishes to clean the machine.
- On Purifier Humidify+Cool models, never wash the water tank cap because it contains electrical power connections; if it gets wet, dry it thoroughly with a dry cloth before refitting.
Safe checks you can perform
- Check whether the LCD alert icon is temporary or continuous
- Switch off and unplug the purifier for 10 seconds
- Inspect the filter air inlet holes and loop amplifier aperture for blockages
- Verify that the water tank cap and evaporator are dry and seated
Leave these tasks to a qualified professional
- Do not attempt this professional task: Dyson Customer Care consultation for a persistent alert icon or code
- Do not attempt this professional task: Inspection or repair by Dyson official service
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.
Dyson Customer Care consultation for a persistent alert icon or code
What they doWhen the continuous alert icon or error code stays on the LCD screen after switching off, unplugging for 10 seconds and switching back on, Dyson Customer Care logs the fault and advises on the next step.
They must show youwhich alert icon or error code is on the LCD screen and that the 10-second unplug step has already been carried out.
In writingthe Dyson support reference number, the machine model and serial number, and the agreed action.
Inspection or repair by Dyson official service
What they doIf Dyson determines that the purifying fan or humidifier has an internal fault after the continuous alert icon refuses to clear, Dyson's official service inspects the unit without the owner opening sealed assemblies.
They must show youthe diagnostic outcome and the machine running without the continuous alert icon on the LCD screen.
In writingthe service report detailing the fault found and any parts repaired or replaced.
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 whether the LCD alert icon is temporary or continuous
- Who:
- you, watching the front LCD screen on the purifier.
- How:
- see whether the alert triangle appears on the LCD screen and then disappears on its own, or stays continuously on the display.
- Result that matters:
- knowing whether the machine only showed a temporary alert or needs the 10-second unplug procedure.
- If the alert icon disappears from the LCD screen:
- Dyson's manual says you can continue to use your machine.
- If the alert icon stays on continuously or an error code is displayed:
- proceed with the 10-second power reset.
- Evidence to keep:
- a photo or short clip of the LCD screen showing the alert icon or error code.
Evidence: Dyson Purifier Humidify+Cool Formaldehyde (PH04) - User manual · Dyson Purifier Cool Formaldehyde (TP09) - User manual
Switch off and unplug the purifier for 10 seconds
- Who:
- you, at the wall socket.
- How:
- switch off the machine, unplug it from the mains supply, leave it unplugged for 10 seconds, then plug it back in and switch it on.
- Result that matters:
- checking whether the continuous alert icon or error code clears when the LCD screen starts up again.
- If the LCD screen returns to normal without the alert icon:
- the reset resolved the condition.
- If the continuous alert icon or error code continues to show on the LCD screen:
- unplug the machine and inspect the air inlets and covers before contacting Dyson.
- Evidence to keep:
- a note of when you ran the 10-second unplug test and whether the icon returned immediately.
Evidence: Dyson Purifier Humidify+Cool Formaldehyde (PH04) - User manual · Dyson Purifier Hot+Cool (HP07) and Purifier Hot+Cool Formaldehyde (HP09) - User manual · Dyson Purifier Hot+Cool Gen1 (HP10) - User manual
Inspect the filter air inlet holes and loop amplifier aperture for blockages
- Who:
- you, with the machine switched off and unplugged.
- How:
- look for blockages in the air inlet holes on the filter and in the small aperture inside the loop amplifier; use a soft brush to remove dust and debris and wipe the outside with a damp lint-free cloth without detergents or polishes.
- Result that matters:
- clearing any dust obstructing airflow and ensuring both outer filter covers click securely into place.
- If debris was blocking the holes or an outer cover was unclipped and the alert clears after refitting:
- keep up regular cleaning as described in the manual.
- If the air inlets and aperture are clear and the covers click in firmly, yet the alert stays:
- check the water tank cap if your model is a humidifier.
- Evidence to keep:
- a photo of the cleaned filter inlet holes and the loop amplifier aperture.
Evidence: Dyson Purifier Humidify+Cool Formaldehyde (PH04) - User manual · Dyson Purifier Cool Formaldehyde (TP09) - User manual · Dyson Purifier Hot+Cool (HP07) and Purifier Hot+Cool Formaldehyde (HP09) - User manual
Verify that the water tank cap and evaporator are dry and seated
- Who:
- you, if you own a Dyson Purifier Humidify+Cool.
- How:
- push down the water tank release buttons on the sides, slide the tank out, check that the cap and its power connections are completely dry (wiping thoroughly with a dry cloth if wet), and slide the evaporator and tank back in until secure.
- Result that matters:
- ruling out moisture on the cap's power connections or an unseated water tank.
- If drying the cap and clicking the tank back into place clears the icon:
- always keep the cap dry when filling or deep cleaning.
- If the continuous alert icon or any other alert icon still shows on the LCD screen:
- contact Dyson Customer Care.
- Evidence to keep:
- a photo of the water tank cap connections and the serial number plate under the base.
Evidence: Dyson Purifier Humidify+Cool Formaldehyde (PH04) - User manual
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
- Appliances
- Brand
- Dyson
- Product type
- Air purifiers
Known code variants
- código de error purificador Dyson
- Continuous alert icon
- Dyson exclamation mark triangle LCD
- Dyson purifier error code
- Dyson purifier warning triangle
- Dyson triángulo exclamación
- Icono de alerta continua
- Icono de alerta temporal
- Temporary alert icon
- Triangle alert icon
- Triángulo de alerta continuo
- Triángulo de alerta temporal
What it means
In the user manuals for Dyson Purifier Humidify+Cool (PH04 and PH2 De-NOx PH05), the Alerts section separates two LCD warnings: the temporary alert icon, which shows briefly and clears so you can continue using the machine, and the continuous alert icon, which requires switching off, unplugging for 10 seconds and plugging back in. In the Purifier Cool Formaldehyde (TP09) and Purifier Hot+Cool (HP07, HP09 and HP10) manuals, Dyson adds under Error codes that if an error code appears you should try turning the machine off and on again. Other models may differ, and this icon alone never proves an internal component is faulty.
Warnings and stop conditions
- Mediumsource verified
Always switch off and unplug the purifier before checking the filters or brushing away dust, and never use detergents or polishes to clean the machine.
Evidence: Dyson Purifier Humidify+Cool Formaldehyde (PH04) - User manual · Dyson Purifier Cool Formaldehyde (TP09) - User manual · Dyson Purifier Hot+Cool Gen1 (HP10) - User manual
- Highsource verified
On Purifier Humidify+Cool models, never wash the water tank cap because it contains electrical power connections; if it gets wet, dry it thoroughly with a dry cloth before refitting.
Evidence: Dyson Purifier Humidify+Cool Formaldehyde (PH04) - User manual
Symptoms and causes
Probable causes · in order
- Momentary event triggering the temporary alert iconCommon
Dyson documents that the temporary alert icon can appear on the LCD screen and then disappear by itself without any lasting fault on the purifier.
Evidence: Dyson Purifier Humidify+Cool Formaldehyde (PH04) - User manual
- System state cleared by a 10-second power cycleCommon
When the continuous alert icon stays on the LCD screen or an error code is shown, Dyson's first step is to switch off, unplug for 10 seconds and switch back on.
Evidence: Dyson Purifier Humidify+Cool Formaldehyde (PH04) - User manual · Dyson Purifier Cool Formaldehyde (TP09) - User manual · Dyson Purifier Hot+Cool (HP07) and Purifier Hot+Cool Formaldehyde (HP09) - User manual · Dyson Purifier Hot+Cool Gen1 (HP10) - User manual
- Dust or blockage in the filter air inlets or loop amplifier aperturePossible
Under Looking after your machine, Dyson stresses checking for blockages in the air inlet holes on the filter and inside the small aperture of the loop amplifier.
Evidence: Dyson Purifier Humidify+Cool Formaldehyde (PH04) - User manual · Dyson Purifier Cool Formaldehyde (TP09) - User manual · Dyson Purifier Hot+Cool (HP07) and Purifier Hot+Cool Formaldehyde (HP09) - User manual · Dyson Purifier Hot+Cool Gen1 (HP10) - User manual
- Wet water tank cap connections or fault needing Dyson supportLess common
On PH04 humidifying purifiers the water tank cap houses electrical power connections that must stay completely dry; if the continuous alert icon remains after the reset, Dyson asks you to contact them.
Evidence: Dyson Purifier Humidify+Cool Formaldehyde (PH04) - User manual
Virtual technician
Does Continuous alert icon 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
- 1
Purificador Dyson Purifier Humidify+Cool PH2 De-NOx (PH05) - Manual del usuario
Dyson · 2026 · official_doc
- 2
Dyson Purifier Humidify+Cool Formaldehyde (PH04) - User manual
Dyson · 2026 · official_doc
- 3
Dyson · 2026 · official_doc
- 4
Dyson Purifier Cool Autoreact (TP7A) - Manual de usuario
Dyson · 2026 · official_doc
- 5
Dyson Purifier Cool Formaldehyde (TP09) - User manual
Dyson · 2026 · official_doc
- 6
Dyson Purifier Hot+Cool (HP07) and Purifier Hot+Cool Formaldehyde (HP09) - User manual
Dyson · 2026 · official_doc
- 7
Dyson Purifier Hot+Cool Gen1 (HP10) - Manual de usuario
Dyson · 2026 · official_doc
- 8
Dyson Purifier Hot+Cool Gen1 (HP10) - User manual
Dyson · 2026 · official_doc
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