- Boilers
- Electric water heater
Err 19
Thermor electric water heater Err 19: power cut in 24 hours
Risk level
Low
Usually safe to check without specialist tools.
Urgency
Low
Quick answer
Err 19 (displayed on the Water Drop touch interface with the top tip lit in red and the two upper-right segments in white) means the water heater detected an electrical power cut within the last 24 hours. Press and hold the centre of the water drop for at least 3 seconds to clear it.
Safety first
Stop and check this first
- Do not leave a Malicio 3, Duralis Connect or Aéromax Access water heater wired to a day/night off-peak contactor or plug-in timer: Thermor states that cutting mains power every day eventually damages the electronics and internal accumulator.
- Any rewiring inside the household electrical distribution panel to bypass an off-peak contactor or tighten 230 V terminals must be carried out exclusively by a qualified electrician with mains power isolated.
Safe checks you can perform
- Confirm the red top tip and two upper-right white segments on the Water Drop display
- Press and hold the centre of the Water Drop touch panel for at least 3 seconds
- Check whether a day/night off-peak contactor is cutting power every day
Leave these tasks to a qualified professional
- Do not attempt this professional task: Rewire the water heater at the panel to a dedicated permanent 24/24 electrical circuit
- Do not attempt this professional task: Set up off-peak heating windows in the Cozytouch app or inspect supply terminals
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.
Rewire the water heater at the panel to a dedicated permanent 24/24 electrical circuit
What they doIf a Malicio 3, Duralis Connect or Aéromax Access water heater is connected through an off-peak day/night contactor or timer switch on the distribution board, have a qualified electrician rewire it to a dedicated circuit breaker providing uninterrupted 24/24 mains power.
They must show youthe electrical panel wiring bypassing the day/night contactor and continuous 230 V supply verified on the dedicated breaker.
In writingthe electrical work certificate confirming permanent 24/24 supply on a dedicated breaker in accordance with Thermor installation requirements.
Set up off-peak heating windows in the Cozytouch app or inspect supply terminals
What they doOnce permanent 24/24 power is established, have the installer configure off-peak heating schedules in the Thermor Cozytouch app (one 12-hour minimum window on Aéromax Access, or up to two windows totalling at least 8 hours on Duralis Connect) or tighten supply terminals if micro-cuts occurred.
They must show youthe active heating schedule in the Thermor Cozytouch app and the Water Drop touch display operating free of Err 19.
In writingthe configured Cozytouch heating time windows or the terminal inspection and voltage stability test on the supply circuit.
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.
Confirm the red top tip and two upper-right white segments on the Water Drop display
- Who:
- you, by looking at the front digital touch interface.
- How:
- inspect the Water Drop panel on the front of the water heater and verify that the top tip is lit in red while the two upper-right segments are lit in white (distinct from the white bottom base used for Err 10).
- Result that matters:
- confirming that the display is showing informational alert Err 19 for a power interruption within the past 24 hours.
- If the top tip is red and the two upper-right segments are white:
- clear the alert by pressing the centre of the water drop.
- If the entire touch display is dark with no segments lit:
- check your electrical distribution board to see if the water heater breaker is off.
- Evidence to keep:
- photo of the Water Drop touch panel showing the red tip and two upper-right white segments.
Evidence: Mon chauffe-eau affiche une erreur, que faire ? · Comment résoudre un problème de ballon d'eau chaude qui affiche une erreur 19 ? · Thermor Ceramics Digital Connect y Genius Steatite WiFi, manual de instrucciones 700U08320150
Press and hold the centre of the Water Drop touch panel for at least 3 seconds
- Who:
- you, at the front touch interface of the water heater.
- How:
- place your finger on the centre of the Water Drop touch display and hold it down for at least 3 continuous seconds to acknowledge and clear Err 19 (or simply wait until 24 hours of uninterrupted power have elapsed).
- Result that matters:
- turning off the red top tip so the Water Drop interface returns to displaying available hot showers normally.
- If the alert clears and does not come back the next day:
- it was caused by first-time commissioning or a one-off power outage.
- If Err 19 comes back every day after off-peak hours end:
- your water heater is wired to a day/night contactor or timer.
- Evidence to keep:
- photo of the Water Drop touch panel after the red tip has cleared.
Evidence: Mon chauffe-eau affiche une erreur, que faire ? · Comment résoudre un problème de ballon d'eau chaude qui affiche une erreur 19 ? · Thermor Ceramics Digital Connect y Genius Steatite WiFi, manual de instrucciones 700U08320150
Check whether a day/night off-peak contactor is cutting power every day
- Who:
- you, at the household electrical panel and in the Thermor Cozytouch app.
- How:
- check your electrical board to see if the water heater circuit runs through an off-peak day/night contactor (contacteur heures creuses) or timer; to heat during off-peak hours on Duralis Connect or Aéromax Access, keep permanent 24/24 mains power and schedule heating windows inside the Thermor Cozytouch app.
- Result that matters:
- preventing daily power cuts that re-trigger Err 19, reduce hot water comfort and prematurely wear out the electronic board and battery.
- If an off-peak contactor controls the circuit:
- set it to forced mode temporarily and have an electrician rewire the heater to permanent power.
- If the heater is already on a permanent 24/24 circuit yet Err 19 recurs without house outages:
- ask an electrician to check for loose supply terminals.
- Evidence to keep:
- photo of the circuit breaker or contactor assigned to the water heater on your electrical panel.
Evidence: Mon chauffe-eau affiche une erreur, que faire ? · Comment résoudre un problème de ballon d'eau chaude qui affiche une erreur 19 ? · Thermor Ceramics Digital Connect y Genius Steatite WiFi, manual de instrucciones 700U08320150
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
- Boilers
- Brand
- Thermor
- Product type
- Electric water heater
Known code variants
- Termo eléctrico Thermor Err 19
- Thermor corte alimentación Err 19
- Thermor Duralis Connect Err 19
- Thermor Err 19
- Thermor Erreur 19
- Thermor Malicio 3 Err 19
- Thermor power cut Err 19
- Thermor punta roja dos segmentos blancos derecha
- Thermor red tip two upper right white segments
- Thermor water heater Err 19
What it means
Thermor's official page "Comment résoudre un problème de ballon d'eau chaude qui affiche une erreur 19 ?" and manual 700U08320150 cover Err 19/Erreur 19 on Malicio 3, Duralis Connect, Aéromax Access, Ceramics Digital Connect and Genius Steatite WiFi. The segmented Water Drop digital touch display shows a red top tip and two white upper-right segments: power was interrupted in the past 24 hours by a grid outage, initial commissioning or incorrect wiring to an off-peak contactor. Models outside these connected ranges may use other alerts. Err 19 alone does not identify a faulty part.
Warnings and stop conditions
- Mediumeditorial warning
Do not leave a Malicio 3, Duralis Connect or Aéromax Access water heater wired to a day/night off-peak contactor or plug-in timer: Thermor states that cutting mains power every day eventually damages the electronics and internal accumulator.
Evidence: Mon chauffe-eau affiche une erreur, que faire ? · Comment résoudre un problème de ballon d'eau chaude qui affiche une erreur 19 ? · Thermor Ceramics Digital Connect y Genius Steatite WiFi, manual de instrucciones 700U08320150
- Higheditorial warning
Any rewiring inside the household electrical distribution panel to bypass an off-peak contactor or tighten 230 V terminals must be carried out exclusively by a qualified electrician with mains power isolated.
Evidence: Mon chauffe-eau affiche une erreur, que faire ? · Comment résoudre un problème de ballon d'eau chaude qui affiche une erreur 19 ? · Thermor Ceramics Digital Connect y Genius Steatite WiFi, manual de instrucciones 700U08320150
Symptoms and causes
Probable causes · in order
- Incorrect wiring to an off-peak day/night contactor or timer clockCommon
Malicio 3, Duralis Connect and Aéromax Access water heaters require permanent 24/24 mains power; wiring them to an off-peak contactor cuts power daily and triggers Err 19 every day.
Evidence: Mon chauffe-eau affiche une erreur, que faire ? · Comment résoudre un problème de ballon d'eau chaude qui affiche une erreur 19 ? · Thermor Ceramics Digital Connect y Genius Steatite WiFi, manual de instrucciones 700U08320150
- Initial commissioning of a brand-new Duralis Connect or Aéromax Access unitPossible
When a newly installed Duralis Connect or Aéromax Access water heater is powered up for the first time, it displays Err 19 as an informational notice during the first 24 hours of continuous supply.
Evidence: Mon chauffe-eau affiche une erreur, que faire ? · Comment résoudre un problème de ballon d'eau chaude qui affiche une erreur 19 ? · Thermor Ceramics Digital Connect y Genius Steatite WiFi, manual de instrucciones 700U08320150
- Temporary household or utility grid power outage in the last 24 hoursPossible
A storm, utility maintenance on the street grid or briefly switching off the breaker at the household panel within the last 24 hours logs Err 19 once power returns.
Evidence: Mon chauffe-eau affiche une erreur, que faire ? · Comment résoudre un problème de ballon d'eau chaude qui affiche une erreur 19 ? · Thermor Ceramics Digital Connect y Genius Steatite WiFi, manual de instrucciones 700U08320150
Virtual technician
Does Err 19 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
Mon chauffe-eau affiche une erreur, que faire ?
Thermor · 2025 · official_doc
- 2
Comment résoudre un problème de ballon d'eau chaude qui affiche une erreur 19 ?
Thermor · 2026 · official_doc
- 3
Thermor Ceramics Digital Connect y Genius Steatite WiFi, manual de instrucciones 700U08320150
Thermor · 2026 · official_doc
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