Daikin Altherma Installer

System Faults: No Heating/No Hot Water/Both/Repeated Error Code

In the scenario that your air source heat pump system is not working correctly or that your controller is displaying an Error Code or Fault Code it will be necessary for a trained Engineer to investigate the nature of the fault and to determine the solution to resolve it. This should only be carried out by a trained and qualified Engineer.

It is important to make note of the Fault Code or Error Code and get in touch to book an urgent maintenance visit. Air2Heat Ltd provide a professional and reliable service, trained, qualified and experienced to diagnose and repair faults on heat pumps including Mitsubishi Electric Ecodan, Samsung EHS, Hitachi Yutaki and Daikin Altherma.


We cover most parts of Powys so please get in touch for any maintenance requirements.

Ecodan Installer
MCS Certified

  • Ecodan L9 Error Code

    An L9 Error Code can occur on a Mitsubishi Electric Air Source Heat Pump when a Flow Sensor or Flow Switch detects low water flow rate on the Primary pipework circuit. 

    The cause is water circulation issues. Contact us for further assistance to resolve the issue.

  • Ecodan U1 Error Code

    A U1 Error Code can occur on a Mitsubishi Electric Air Source Heat Pump due to a High Pressure fault usually related to abnormal water flow on the Primary pipework circuit. To resolve the matter please get in touch to arrange a Site visit.

  • Samsung E912 Error Code

    An E912 Error Code can occur on a Samsung air source heat pump system when water flow is detected with no demand. The cause can often be Secondary pipework circuit related including secondary pumps or hydraulic separation. It is likely the system wiring will need checking. Contact us to arrange a Site Visit to resolve the fault

  • Samsung E911 Error Code

    A Samsung E911 Error Code can often occur on a Samsung air source heat pump system when there is a water flow issue in the system, more often in the Primary pipework circuit. 

    The cause is often triggered by low fow rates or no flow. In the event that the system water pressure is correctly set and not the issue, it will be necessary to inspect the system for any hydraulic issues and to test system components including flow switch and to electronically test the unit. New components may be required. To resolve the fault contact us to arrange a Site visit

  • Hitachi 070 Alarm Code

    A Hitachi Yutaki air source heat pump can display a 070 Alarm Code or Fault Code if the system has low flow rates (m3/hr). Whilst a blocked filter can sometimes be the underlying cause, this 070 Alarm can also relate to faulty system components or system wiring. To resolve the issue please contact us to arrange a site visit. 

  • Hitachi 083 Alarm Code

    A Hitachi Yutaki air source heat pump can display an 083 Alarm Code when the system pressure is low for more than 60 Seconds whilst a pump is still in operation. The alarm will force the system to stop. Once the system pressure has been topped up correctly the system can be restarted and the Alarm should clear. In the event this continues to be an issue, contact us to arrange a Site visit. 

  • Daikin 7H-01 Error Code

    A Daikin Altherma air source heat pump can display a 7H-01 Error Code on the Controller display screen when water flow rates are abnormal. 

    If the water pressure is low it can be topped up and the system reset and this may resolve the issue. However, in the event that there are no system water quality issues and the water pressure is set correctly it may be necessary to diagnose the system components including flow sensors, water pump, 3 way valve, bypass and any hydraulic separation on the system. To resolve the issue contact us to arrange a Site visit. 

  • Daikin C0-00 Error Code

    A C0-00 Error Code can normally occur on a Daikin Altherma air source heat pump when the Flow Sensor detects water flow 45 seconds after the water pump has stopped. This will prevent the heat pump from running. The system will likely require inspecting to correctly diagnose the cause. In many cases the issues can be related to low water flow rates, issues with hydraulic separation and secondary circuit related components. 

    To resolve to issue get in touch to arrange a Site visit. 

To arrange scheduled servicing for your air source heat pump please get in touch via the CALL button above or drop us an email - info@air2heat.co.uk