7H • Daikin • Altherma 3
Fault code 7H Daikin Altherma 3: quick diagnosis
Fault code 7H (often with a suffix depending on the model) indicates a defect detected by the control system. The aim is to identify whether the cause is hydraulic, sensor, or control related.
Proof status : Manufacturer reference needed for the exact range
Source: Daikin documentation (installer/service manual – according to product reference)
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 7H on Daikin Altherma 3 means: Fault code 7H (often with a suffix depending on the model) indicates a defect detected by the control system. The aim is to identify whether the cause is hydraulic, sensor, or control related. Most common cause: Depending on the variant, a 7H can be linked to a temperature/sensor inconsistency, insufficient flow, or an abnormal state detected by the regulation. First action: Check installation pressure and bleed air.. Call a registered engineer if the fault returns after basic checks or involves refrigerant work (F-Gas registered engineer required).
According to Daikin documentation, the minimum water flow for EHSH/EHSHB/EHSX/EHSXB units is 12 l/min, and for EBSH/D.EBSHB units it is 16 l/min in cooling and 22 l/min in heating or defrost.
Continue this diagnosis in Marcel
Daikin code 7H: Marcel picks this code up for Altherma 3 and guides you, with the manufacturer reference when one exists.
For regular use on site: Install the app
What does fault code 7H on Daikin mean?
Fault code 7H (often with a suffix depending on the model) indicates a defect detected by the control system. The aim is to identify whether the cause is hydraulic, sensor, or control related.
Depending on the variant, a 7H can be linked to a temperature/sensor inconsistency, insufficient flow, or an abnormal state detected by the regulation.
Symptoms
- Heating cuts out
- Domestic hot water not produced or intermittent
- Inconsistent flow/return temperature
- Message 7H on controller
Diagnosis
1. Check hydraulics (flow/filter)
- Check installation pressure and bleed air.
- Check filter/dirt separator if present and clean if necessary.
- Ensure valves are open and the circulator pump is running.
2. Check sensors and measurements
- Compare displayed temperatures with an external measurement.
- Check sensor condition (fixing, insulation, connections).
- Look for an abnormal value that triggers the safety.
3. Confirm via history and test modes
- Read the fault history to identify the triggering moment.
- Use a manufacturer test mode if available to isolate a component.
- Then apply the Daikin procedure corresponding to the exact sub-code.
Repair and return to service — Daikin fault 7H
In many cases, restoring correct flow (bleeding, filter) or fixing a poorly fitted sensor is enough. To avoid an approximate diagnosis, base it on the exact 7H sub-code and the manufacturer's procedure.
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 Daikin Altherma 3.
Affected models
- Altherma 3 (EBSH/D.EBSHB Series)
- Altherma 4 (EHSH/EHSHB/EHSX/EHSXB Series)
- Altherma 3 (EHSH/EHSHB/EHSX/EHSXB Series)
- Altherma 4 (EBSH/D.EBSHB Series)
- Altherma 3 (EBSX/EBSXB Series)
- Altherma 4 (EBSX/EBSXB Series)
Field context
Frequently occurs during commissioning or after hydraulic modification (valve closure, bleeding). The installer must absolutely check the actual flow in all loops, including those controlled by valves, to ensure it exceeds the critical threshold (12 or 22 l/min).
Frequently asked questions
What is the minimum water flow required to trigger fault code 7H?
The threshold depends on the model and operating mode. For EHSH/EHSHB/EHSX/EHSXB units, the minimum flow is 12 l/min (sources 4, 5, 6). For EBSH/D.EBSHB units, it is 16 l/min in cooling and 22 l/min in heating or defrost (source 1). If this flow is not achieved, the unit stops and displays 7H.
Can fault code 7H occur if loop valves are closed?
Yes. The manuals specify that the minimum flow must be guaranteed even if all loop valves are closed (sources 5, 6). The system checks the overall hydraulic capacity of the installation. If circulation is blocked or insufficient in certain configurations, fault code 7H will be generated to protect the unit.
What procedure should be followed to diagnose and correct fault code 7H?
First, identify the exact model to know the flow threshold (12, 16, or 22 l/min). Then, consult the section dedicated to checking flow and water volume in the specific installation manual (e.g., section 8.1.3 for Altherma 4, section 8.2 for EBSH) to measure the actual flow and carry out bleeding or valve adjustment as necessary.
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:
