Nibe S2125, Installer Manual, Page: 22 / 64

General
Pipe installation must be carried out in accordance with
current norms and directives.
The pipe dimension should not be less than the recommen-
ded pipe diameter according to the table. However, each
system must be dimensioned individually to manage the
recommended system flows.
MINIMUM SYSTEM FLOWS
The installation must be dimensioned to manage at least
the minimum defrosting flow at 100% pump operation, see
table.
Minimum re-
commended
pipe dimen-
sion (mm)
Minimum re-
commended
pipe dimen-
sion (DN)
Minimum flow
duringdefrost-
ing
(100% pump
speed (l/s)
Air/waterheat
pump
28 25 0.32
S2125-8
(1x230V)
S2125-8
(3x400V)
S2125-12
(1x230V)
S2125-12
(3x400V)
NOTE
An undersized system can result in damage to the
product and lead to malfunctions.
S2125 can only operate up to a return temperature of about
65 °C and an outgoing temperature of about 75 °C from the
heat pump.
S2125 is not equipped with shut-off valves on the heating
medium side, rather these must be installed to facilitate any
future servicing. The return temperature is limited by the
return line sensor.
WATER VOLUMES
To avoid short operating times and to enable defrosting, a
certain available water volume is required. For the optimum
operation of S2125, a minimum available water volume of
120 litres is recommended. This applies separately to heating
and cooling systems.
NOTE
The pipe installation must be flushed out before
the heat pump is connected so debris cannot
damage component parts.
Symbol key
Meaning Symbol
Shut-off valve
Circulation pump
Expansion vessel
Filterball
Pressure gauge
P
Safety valve
Trim valve
Reversing valve/shunt
Control module
Air/water heat pump
Radiator system
Domestic hot water
Water heater
NIBE S2125 Chapter 4 | Pipe connections 22
Pipe connections