Daikin EPRA08EAV3, Installer'S Reference Manual

Page: 86 / 292

8 | Piping installation
Installer reference guide
86
EPRA08~W1 + ETVH/9W
Daikin Altherma 3 H MT F
4P634886-1 – 2021.03
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 "11.4 Checklist during
commissioning" [ 4 224].
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.
a
a Schrader valve
8.1.5 To check the water volume: Examples
Example 1
The indoor unit is installed 5 m below the highest point in the water circuit. The
total water volume in the water circuit is 100 l.
No actions or adjustments are required.
Example 2
The indoor unit is installed at the highest point in the water circuit. The total water
volume in the water circuit is 250 l.