
9HK 200S
HK 200S-6
4 Pipe connections
General pipe connections
The piping installation must be executed according to
the applicable standards and directives.
HK 200S / HK 200S-6 indoor unit NIBE SPLIT out-
door air heat pump, and controller NIBE SMO form a
complete heating system.
The system can cooperate with a low- and medium-
temperature heating system. Recommended temper-
ature of the heating medium at minimum designed
outdoor temperature DOT must not exceed 55°C on
supply, and 45 °C on return circuit from the heating
system, whereas HK 200S / HK 200S-6 can achieve
even 65 °C when using a ow-through heating mod-
ule or another peak heat source.
Excess medium owing out of the safety valve must
be discharged via a pipe to a oor drain. The over-
ow pipe must be slanted at the entire length from the
safety valve, and must be secured against freezing.
In order to achieve maximum system efciency, we
recommend the installation of HK 200S / HK 200S-6
as close to the heat pump as possible.
The HK 200S / HK 200S-6 module is not equipped
with cut-off valves, which must be installed outside
the indoor module to make future maintenance eas-
ier. The HK 200S / HK 200S-6 module can be con-
nected to the central heating, cooling, and domestic
hot water installation. Install the supplied safety valve
and the manometer.
HK 200S / HK 200S-6 is equipped with a diaphragm
expansion vessel for a heating circuit of 10 I. Initial
pressure of the expansion vessel must be set appro-
priately to the maximum height (H) between the ves-
sel and the highest heater, see the drawing. The ini-
tial pressure of 0.5 bar (5 mvp) shall mean maximum
permissible height difference of 5 m.
If the standard initial pressure in the diaphragm ex-
pansion vessel is too low, it can be raised by lling the
vessel through the valve installed.
Any change to the initial pressure affects the dia-
phragm expansion vessel’s capacity to support the
increase in water volume.
IMPORTANT
All places in the heating system located high must be
equipped with vents.
IMPORTANT
Pipelines must be rinsed before connecting the indoor
module so that possible dirt does not damage its ele-
ments.
IMPORTANT
As long as heating circuits in the system have not been
lled with the heating medium, do not set the switch
(SF1) in the SMO module in position “I” or “ ”. The
compressor in the heat pump and the ow-through
heating module can be damaged.
Capacities of the indoor unit and the
heating system
System requirements
The inner capacity of HK 200S / HK 200S-6 for the
purposes of calculating the diaphragm expansion
vessel in the domestic hot water installation totals
180 l. The capacity of the diaphragm expansion ves-
sel must constitute at least 5% total capacity.
Minimum required conguration:
In order to assure correct operation, the capacity of
the heating system must meet the requirements for
the installation. If this condition has not been met, in-
stall an additional buffer tank.
CAUTION
In this case a diaphragm expansion vessel of the
DHW installation must have the capacity of 10l. The
diaphragm expansion vessel at the domestic hot water
installation is not required. It is, however, required to
install a safety valve with opening pressure of 6 bar.
IMPORTANT
All connections require free ow, hence a discharge
valve must be installed.
Chapter 4 | Pipe connections