- Heat pumps
- Air-to-water heat pump
E912
Samsung E912 on an EHS heat pump: flow detected with the pump off
Risk level
Low
Usually safe to check without specialist tools.
Urgency
Medium
Quick answer
On Samsung EHS units, E912 means the flow switch detects normal flow for 10 minutes while the pump signal is off. Note the code and the mode, do not open the unit and call the Samsung technician.
Safety first
Stop and check this first
- Samsung says not to attempt to repair, disassemble or modify the product yourself. The R290 Mono uses flammable refrigerant: Samsung requires service engineers not to use ignition sources and, for a leaking unit, no ignition source within 6 metres.
Safe checks you can perform
- Code and system state
- Other equipment on the system
- Flow with the pump off and flow switch
Leave these tasks to a qualified professional
- Do not attempt this professional task: Check whether the flow is real
- Do not attempt this professional task: Check the switch before replacing it
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.
Check whether the flow is real
What they doThe technician measures flow with the unit's pump stopped and compares it with Samsung's threshold.
They must show youthe reading with the pump off and your unit's capacity.
In writingwhether the flow was real and what was corrected.
Check the switch before replacing it
What they doIf there is no real flow, the technician checks the flow switch connection before replacing it.
They must show youthe connector checked and the switch reading with the pump off and on.
In writingany part replaced and the test without E912.
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.
Code and system state
- Who:
- you.
- How:
- note the code, the time and whether the heat pump was stopped or on standby at that moment.
- Result that matters:
- Samsung only gives E912 after 10 minutes of flow with the pump signal off.
- If the unit was on standby:
- it fits the definition; the technician must check whether the flow is real.
- If it appears together with E911:
- there is a flow reading problem; tell the technician.
- Evidence to keep:
- a photo of the controller with the code.
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
Other equipment on the system
- Who:
- you.
- How:
- note whether your system has another boiler, tank or pump running at the same time as the heat pump.
- Result that matters:
- information so the technician knows whether there can be real flow with the Samsung pump off.
- If other equipment with a pump exists:
- tell the technician; real flow is possible.
- If there is none:
- real flow is less likely; the switch becomes more likely.
- Evidence to keep:
- a list of equipment connected to the circuit.
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
Flow with the pump off and flow switch
- Who:
- the Samsung technician.
- How:
- with the unit's pump stopped, they check for real flow and inspect the flow switch and its connection.
- Result that matters:
- real flow against 7 l/min up to 9 kW or 12 l/min above 9 kW with the pump off.
- If there is real flow:
- the cause is in the hydraulic system, not the unit.
- If there is no flow but the controller sees it:
- the flow switch or its wiring is confirmed.
- Evidence to keep:
- a job sheet with the reading and the switch condition.
Requires opening the unit with power off. Samsung technician only.
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
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
- EHS 912
- Samsung EHS E912
- Samsung heat pump E912
What it means
Samsung defines E912 as a normal flow rate error: the controller sees flow for 10 minutes even though the water pump signal is off. The R290 Mono manual lists it as a flow switch closed error. The threshold is over 7 l/min on units up to 9 kW and over 12 l/min above 9 kW. Water may really be moving through the unit with its pump stopped, or the switch may report flow that is not there. The code does not say which.
Warnings and stop conditions
- Highsource verified
Samsung says not to attempt to repair, disassemble or modify the product yourself. The R290 Mono uses flammable refrigerant: Samsung requires service engineers not to use ignition sources and, for a leaking unit, no ignition source within 6 metres.
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
Symptoms and causes
Probable causes · in order
- Flow switch reading closedPossible
Samsung calls it a flow switch closed error. If there is no real flow, the switch or its signal gives a false reading.
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
- Water moving with the pump offPossible
If the controller measures real flow above the threshold with its pump off, another part of the system is moving the water. Only a measurement with the pump off separates it.
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
Virtual technician
Does E912 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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