- Heat pumps
- Air-to-water heat pump
E919
Samsung E919 on EHS heat pump: DHW disinfection cycle incomplete
Risk level
Medium
Proceed carefully and stop if the check is unclear.
Urgency
Medium
Quick answer
Code E919 or 919 on a Samsung EHS heat pump means the hot water tank disinfection operation did not reach its target temperature or failed to hold it for the required time, so check whether heavy hot water draw or Peak Power limiting occurred and book a technician if the fault recurs.
Safety first
Stop and check this first
- Do not open the Hydro Unit electrical box or attempt to bypass booster heater thermal cut-outs yourself: the auxiliary heater operates on mains voltage and must be inspected only by a qualified technician.
- Water inside the cylinder reaches 70 °C to 75 °C during disinfection operation; run hot taps carefully to avoid scalding and do not permanently disable tank disinfection without professional advice.
Safe checks you can perform
- Note error code E919 or 919 and read the DHW tank temperature on screen
- Check whether hot water was drawn during the scheduled disinfection period
- Look for Peak Power or Smart Grid restriction icons on the wired remote
Leave these tasks to a qualified professional
- Do not attempt this professional task: Test Booster Heater operation, capacity, and Tank Temp. sensor via Self-Test Mode
- Do not attempt this professional task: Audit FSV 304* disinfection settings (#3041 to #3046) and Peak Power parameters (#5041/#5042)
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.
Test Booster Heater operation, capacity, and Tank Temp. sensor via Self-Test Mode
What they doFollowing Samsung's troubleshooting note for E919, the technician must verify booster heater capacity, test for booster heater failure or tripped thermal protection, and run the Booster Heater ON/OFF and Tank Temp. checks in Self-Test Mode.
They must show youthe Booster Heater activation and current draw during Self-Test Mode along with an accurate Tank Temp. sensor reading.
In writingthe electrical test results for the booster heater, any replaced component references, and the official Samsung service job or case number.
Audit FSV 304* disinfection settings (#3041 to #3046) and Peak Power parameters (#5041/#5042)
What they doAn authorised installer or service technician should inspect FSV #3042 (day), #3043 (start time), #3044 (target temp), #3045 (hold duration), and #3046 (maximum duration), and verify that Peak Power Control (#5041/#5042) is not forcing the Booster Heater off during the disinfection window.
They must show youthe current FSV values for #3041 through #3046 and the Peak Power configuration #5041/#5042 on the wired remote controller.
In writingthe documented FSV settings adjusted for the cylinder capacity and confirmation that auxiliary heating is permitted during scheduled disinfection.
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.
Note error code E919 or 919 and read the DHW tank temperature on screen
- Who:
- you.
- How:
- look at the Samsung EHS wired remote display and write down whether it shows E919 or 919 together with the current DHW storage temperature without opening any unit cover.
- Result that matters:
- having the error code and current tank temperature recorded safely for the technician.
- If normal daily hot water heating still reaches its standard setpoint:
- the issue likely affects only the high-temperature booster stage.
- If the cylinder stays cold even during normal DHW demand:
- arrange prompt inspection of the booster heater and hydraulic loop.
- Evidence to keep:
- photo of the wired remote screen showing E919 or 919 and the displayed Tank Temp. value.
Evidence: Samsung EHS air to water heat pump wired remote controller and control kit user manual DB68-08470A-18 · Samsung EHS Mono R290 outdoor unit AE***CXYD** installation manual DB68-12496A-03
Check whether hot water was drawn during the scheduled disinfection period
- Who:
- you.
- How:
- consider whether baths or showers were used during the scheduled disinfection window (default Friday starting at 23:00 under FSV #3042 and #3043), which can drain heat from the cylinder before the hold time finishes.
- Result that matters:
- confirming whether heavy household hot water demand coincided with the disinfection cycle.
- If hot water was used heavily during that window:
- ask your installer about shifting the start time in #3043.
- If no hot water was drawn overnight:
- have a technician inspect the booster heater and FSV parameters.
- Evidence to keep:
- note of the day and time window when error E919 appeared.
Evidence: Samsung EHS air to water heat pump wired remote controller and control kit user manual DB68-08470A-18
Look for Peak Power or Smart Grid restriction icons on the wired remote
- Who:
- you.
- How:
- inspect the status icons on the wired controller screen to see if Peak Power Control or utility Smart Grid load shedding was active and blocking the booster heater.
- Result that matters:
- identifying whether an external power-limiting signal prevented auxiliary electric heating.
- If a power-limiting icon is active:
- inform your installer so they can review #5041/#5042 or reschedule disinfection.
- If no load-shedding icon is active and E919 repeats:
- book an authorised Samsung service technician.
- Evidence to keep:
- photo of the status bar icons on the wired remote controller screen.
Evidence: Samsung EHS air to water heat pump wired remote controller and control kit user manual DB68-08470A-18
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
- Heat pumps
- Brand
- Samsung
- Product type
- Air-to-water heat pump
Known code variants
- 919
- desinfeccion incompleta ACS Samsung EHS
- disinfection operation incomplete Samsung EHS
- E 919
- E919 Samsung EHS
- error E919 aerotermia Samsung
- fallo 919 ClimateHub Samsung
- Samsung ClimateHub code 919
- Samsung EHS E919
- Samsung heat pump error E919
What it means
In the Samsung EHS wired remote controller user manual DB68-08470A-18 and EHS Mono R290 installation manual DB68-12496A-03 (covering Hydro Units, ClimateHub tanks, and AE***CXYD** outdoor units with the MIM-E03EN controller), error 919 (E919) is defined as Disinfection Operation Incomplete Error. Other Samsung EHS generations may differ in menu layout. Samsung's manual notes that disinfection requires a connected booster heater and stops once the maximum duration set in FSV #3046 (default 8 hours) expires; the code alone never proves the booster heater has failed, because simultaneous hot water usage or a Peak Power cut-off can prevent holding target temperature.
Warnings and stop conditions
- Higheditorial warning
Do not open the Hydro Unit electrical box or attempt to bypass booster heater thermal cut-outs yourself: the auxiliary heater operates on mains voltage and must be inspected only by a qualified technician.
Evidence: Samsung EHS air to water heat pump wired remote controller and control kit user manual DB68-08470A-18 · Samsung EHS Mono R290 outdoor unit AE***CXYD** installation manual DB68-12496A-03
- Mediumeditorial warning
Water inside the cylinder reaches 70 °C to 75 °C during disinfection operation; run hot taps carefully to avoid scalding and do not permanently disable tank disinfection without professional advice.
Evidence: Samsung EHS air to water heat pump wired remote controller and control kit user manual DB68-08470A-18
Symptoms and causes
Probable causes · in order
- Booster heater failure, disconnection, or insufficient heating capacityCommon
Manual DB68-08470A-18 states that disinfection can start only if a booster heater is connected and explicitly instructs checking booster heater capacity and booster heater failure when E919 occurs over the maximum duration.
Evidence: Samsung EHS air to water heat pump wired remote controller and control kit user manual DB68-08470A-18
- Maximum duration #3046 elapsed before reaching or holding #3044 and #3045Common
The DHW tank fails to reach the disinfection target temperature (#3044, default 70 °C) or cannot maintain it for the requested holding duration (#3045, default 10 minutes) within the maximum allowed window (#3046, default 8 hours).
Evidence: Samsung EHS air to water heat pump wired remote controller and control kit user manual DB68-08470A-18
- Booster heater forced off by Peak Power Control (FSV #5041/#5042) or Smart Grid signalPossible
When Peak Power Control is configured to force the Booster Heater off (settings 1 or 3 in #5041/#5042) or Smart Grid Mode 1 (Forced thermo off) is active, auxiliary electric heating is inhibited during the scheduled run.
Evidence: Samsung EHS air to water heat pump wired remote controller and control kit user manual DB68-08470A-18
- Heavy domestic hot water draw during the scheduled disinfection window (#3042 and #3043)Possible
Drawing large volumes of hot water while disinfection is running (factory-scheduled for Friday at 23:00 via FSV #3042 and #3043) cools the cylinder and prevents completion before the timer expires.
Evidence: Samsung EHS air to water heat pump wired remote controller and control kit user manual DB68-08470A-18
Virtual technician
Does E919 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
- 2
Samsung EHS Mono R290 outdoor unit AE***CXYD** installation manual DB68-12496A-03
Samsung · 2026 · manual
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