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Piping installation
Installer reference guide
87
EPRA14~18D + ETVH/23E
Daikin Altherma 3 H HT F
4P644737-1A – 2022.03
Minimum flow rate
Check that the minimum flow rate in the installation is guaranteed in all conditions.
This minimum flow rate is required during defrost/backup heater operation. For
this purpose, use the overpressure bypass valve delivered with the unit, and
respect the minimum water volume.
Minimum required flow rate
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For E models: 25 l/min
▪
For E7 models: 20 l/min
NOTICE
To guarantee proper operation it is recommended to have a minimum flow of 28 l/
min during DHW.
NOTICE
If glycol was added to the water circuit, and the temperature of the water circuit is
low, the flow rate will NOT be displayed on the user interface. In this case, the
minimum flow rate can be checked by way of the pump test (check that the user
interface does NOT display error 7H).
NOTICE
When circulation in each or certain space heating loops is controlled by remotely
controlled valves, it is important that the minimum flow rate is guaranteed, even if all
valves are closed. In case the minimum flow rate cannot be reached, a flow error 7H
will be generated (no heating or operation).
See the recommended procedure as described in
8.1.4 Changing the pre-pressure of the expansion vessel
NOTICE
ONLY a licensed installer may adjust the pre-pressure of the expansion vessel.
The default pre-pressure of the expansion vessel is 1 bar. When it is required to
change the pre-pressure, take following guidelines into account:
▪
Only use dry nitrogen to set the expansion vessel pre-pressure.
▪
Inappropriate setting of the expansion vessel pre-pressure will lead to
malfunction of the system.
Changing the pre-pressure of the expansion vessel should be done by releasing or
increasing nitrogen pressure through the Schrader valve of the expansion vessel.
