What it means
Daikin uses other 7H sub codes for flow problems in particular modes: 7H-04 during hot water production, 7H-05 during heating, 7H-06 during cooling or defrost, and 7H-07 when pump deblocking is active. The Altherma 3 R ECH2O guide also lists 7H-08 for a pump abnormality. Daikin's service manual says 7H-04, 7H-05 and 7H-06 have to be reset at the controller.
What to check, in order
- Give it some time
Daikin's installer reference guide says that when the flow drops below the minimum, the unit stops for a while, shows 7H-01 and then resets itself and carries on.
- Check the water pressure
The pressure is shown on the controller's home screen. Daikin's user guides say to check regularly that it is above 1 bar. If it is lower, tell your installer.
- Check the valves are open
Daikin UK's homeowner support page says to check the shut-off valves when there is a flow fault. Make sure the valves on the water pipes to the heat pump are fully open.
- Read the help text
On the controller, open the main menu and choose Malfunctioning to see the code and a short description. The help button gives a longer one. Note the code for your installer.
When to call your installer
If the code keeps coming back, call your installer. Daikin UK also suggests checking the filters and checking for air in the circuit. Daikin's service manual lists these causes for an engineer to check: a closed stop valve, air in the water circuit, low water flow or pressure, no bypass fitted, a dirty filter, or a faulty flow sensor, 3-way valve, water pump or hydro PCB.
Quick answers
What does the Daikin Altherma 7H-01 error code mean?
Not enough water is flowing round the heating circuit, so the heat pump has stopped for the moment. Daikin uses other 7H sub codes for flow problems in particular modes: 7H-04 during hot water production, 7H-05 during heating, 7H-06 during cooling or defrost, and 7H-07 when pump deblocking is active. The Altherma 3 R ECH2O guide also lists 7H-08 for a pump abnormality. Daikin's service manual says 7H-04, 7H-05 and 7H-06 have to be reset at the controller.
Can I fix Daikin Altherma 7H-01 myself?
Easy (about 10 minutes). Start with: give it some time; check the water pressure; check the valves are open. If the code keeps coming back, call your installer. Daikin UK also suggests checking the filters and checking for air in the circuit. Daikin's service manual lists these causes for an engineer to check: a closed stop valve, air in the water circuit, low water flow or pressure, no bypass fitted, a dirty filter, or a faulty flow sensor, 3-way valve, water pump or hydro PCB.
Is Daikin Altherma 7H-01 worth repairing?
Worth fixing. Often a simple cause such as low pressure, a closed valve, a dirty filter or trapped air. A failed pump or flow sensor is a bigger repair.
Checked against
- Daikin Altherma 3 R W installer reference guide 4P496758-1B (ERGA-D, EHBH/EHBX-D), troubleshooting and error codes, p. 89 (ManualsLib copy)
- Daikin Altherma 3 R ECH2O installer reference guide, error codes overview, p. 274 (ManualsLib copy)
- Daikin Altherma 3 R ECH2O installer reference guide, error code notes, p. 277 (ManualsLib copy)
- Daikin service manual ESIE20-06A, Daikin Altherma 3 M (EBLA/EDLA), PDF (copy hosted on the OpenEnergyMonitor forum)
- Daikin Altherma low temperature split user reference guide 4P499574-1A (EHVH04/08S23DAV), PDF
- Daikin Altherma 3 H HT F+W operation manual 4P586455-1C, PDF
- Daikin UK: Homeowner support
Last reviewed October 2026. Manufacturers update their pages, and your manual is the final word. Spotted a mistake? Email contact@appliance-error-codes.com.