Daikin Altherma fault 7H
Flow error (minimum flow rate not reached)
Heat pumpWhat it means
Flow error generated when the minimum required flow rate cannot be reached in the water circuit, resulting in no heating or operation.
Likely causes
- Remotely controlled valves in space heating loops closed, restricting circulation
- Minimum flow rate of 22 l/min not guaranteed in the installation
- Delay after filling water circuit before commissioning can block pump rotor
Where to start
- Check that the minimum flow rate is guaranteed in all conditions, even if all valves are closed
- Install the water filter in the correct location
- Install the 2 clips to fix the water filter to the water circuit pipes
The full answer, free
- 3 more checks in order
- The readings and component tests from the manual
- How to put it right, step by step
- The manual page for this fault (page 17), right under the answer
Safety: Isolate the outdoor unit and any backup heater, and give the inverter capacitors time to discharge before you open the electrics. Anything on the refrigerant circuit needs F-gas certification.
From the Daikin manual for the Altherma. Check the model on the data plate before you order parts.
Other Daikin Altherma fault codes
- 4-02Incorrect setting of space heating OFF temperature
- 7H-01Water flow problem
- 7H-04Water flow problem during domestic hot water production
- 7H-05Water flow problem during heating/sampling
- 7H-06Water flow during cooling/defrost
- 7H-07Water flow problem. pump de-blocking active
- 7H-XXWater flow or volume too low
- 80-00Inlet water thermistor abnormality
- 81-00Outlet water thermistor abnormality
- 81-01Mixed water thermistor abnormality
- 89-01Heat exchanger frozen
- 89-02Heat exchanger frozen
- 89-03Heat exchanger frozen
- 8F-00Abnormal increase outlet water temperature (domestic hot water)
- 8H-00Abnormal increase outlet water temperature
- 8H-01Overheating mixed water circuit
- 8H-02Overheating mixed water circuit (thermostat)
- 8H-03Safety thermostat circuit open with jumper removed
- A1-00Zero cross detection problem
- A5-00Outdoor unit: high pressure peak cut / freeze protection problem
- AA-01Backup heater overheated
- AA-02External backup heater overheated
- AC-00Booster heater overheated
- AH-00Tank disinfection function not completed correctly