356 • Atlantic • Air-to-water heat pump
Fault Code 356 Atlantic: insufficient water flow
According to the Atlantic FAQ, code 356 means the heat pump's water flow is below 10 litres per minute: the flow is insufficient.
Proof status : Manufacturer reference listed — check model coverage
Source: Atlantic FAQ — What does error 356 mean on my heat pump? (updated 26/08/2025)
Founder, AskMarcel.app
Founder of AskMarcel.app. Sheets are written from manufacturer documentation; the reference is shown when it has been verified.
In brief
Fault code 356 on Atlantic Air-to-water heat pump means: According to the Atlantic FAQ, code 356 means the heat pump's water flow is below 10 litres per minute: the flow is insufficient. Most common cause: Atlantic lists several possible origins: a configuration error, the failure of a heat pump component, or an electrical problem. The code alone does not identify the faulty component. First action: Switch the unit off with the On/Off button for 2 minutes, then back on (step described by Atlantic).. Call a registered engineer if the fault returns after basic checks or involves refrigerant work (F-Gas registered engineer required).
According to the Atlantic FAQ (updated 26/08/2025), code 356 corresponds to a water flow below 10 litres per minute.
Continue this diagnosis in Marcel
Atlantic code 356: Marcel picks this code up for Air-to-water heat pump and guides you, with the manufacturer reference when one exists.
For regular use on site: Install the app
What does fault code 356 on Atlantic mean?
According to the Atlantic FAQ, code 356 means the heat pump's water flow is below 10 litres per minute: the flow is insufficient.
Atlantic lists several possible origins: a configuration error, the failure of a heat pump component, or an electrical problem. The code alone does not identify the faulty component.
Symptoms
- Code 356 shown on the heat pump interface
- Water flow below 10 l/min
Diagnosis
1. Reset by power cut
- Switch the unit off with the On/Off button for 2 minutes, then back on (step described by Atlantic).
2. Installer checks if the code persists or returns
- Sufficient opening of thermostatic valves (if radiators).
- Opening of the installation valves.
- Settings.
- Flow meter wiring.
- Proper circulation of the heating water.
- Bleeding of the circuit.
Repair and return to service — Atlantic fault 356
Cut the power for 2 minutes, then switch back on. If the code persists or returns, have a professional installer check the installation using the list above.
When should you call an F-Gas engineer?
Contact an F-Gas registered engineer if the fault returns after basic checks, involves refrigerant charging, or requires PCB or compressor replacement on Atlantic Air-to-water heat pump.
Field context
The Atlantic FAQ names no single component: check what limits the flow (valves, bleeding, circulation) before concluding on the flow meter.
Technical source data
Atlantic links 356 to water flow below 10 l/min and lists, for the installer: thermostatic and installation valves, settings, flow meter wiring, water circulation and bleeding.
Frequently asked questions
What does code 356 mean on an Atlantic heat pump?
According to Atlantic, the water flow is below 10 litres per minute: the flow is insufficient.
Is a 2-minute power cut enough?
Atlantic suggests it as a first step. If the code persists or returns, an installer must check valves, settings, flow meter wiring, circulation and bleeding.
Need help with this diagnosis?
Marcel reads your error codes and walks you through them step by step, with sourced answers.
Or keep going right now in your browser:
