Nibe S1156 - Hot Water Circulation Control; Buffer Vessel (UKV) Information; Buffer Vessel Volume Considerations; Alternative Installation Methods

The sensor is placed in the middle of the water heater.
• displayed hot water sensor (BT7)
1
The sensor is optional and is placed in the top of the water
heater.
• shut-off valve
• non-return valve
• enclosed expansion relief valve (FL1)
• mixing valve
A mixing valve must be installed when the factory setting
for hot water is changed. National regulations must be
observed.
• pressure relief valve
• expansion vessel
The expansion vessel (CM4) accommodates expansion
that results from heating the water inside the unit. The
expansion vessel must be connected between the expan-
sion relief valve (FL1) and the water heater. The location
of the expansion vessel should allow access to recharge
the pressure when neccessary.
• tundish
1
The sensor is factory fitted on some water heater/accumulator
tank models from NIBE.
XL9
XL2
Installation alternative
S1156 can be installed in several different ways, some of
which are shown here.
Further option information is available at nibe.co.uk and in
the respective assembly instructions for the accessories
used. See page 70 for a list of the accessories that can be
used with S1156.
HOT WATER CIRCULATION
A circulation pump can be controlled by S1156 to circulate
the hot water. The circulating water must have a temperat-
ure that prevents bacterial growth and scalding, and national
standards must be satisfied.
The HWC return is connected to a freestanding water heater.
The circulation pump is activated via the AUX output in menu
7.4 -"Selectable in/outputs".
HWC can be supplemented with a hot water sensor for HWC
(BT70) and (BT82), which is connected via the AUX input
and activated in menu 7.4 -"Selectable in/outputs".
-QZ1-FQ3
-QZ1-GP11
-QZ1-RM1
-QZ1-RN1
-QZ1
BUFFER VESSEL (UKV)
UKV is an accumulator tank that is suitable for connection
to a heat pump or another external heat source, and can
have several different applications.
For further information, see the Installer Manual for the ac-
cessory.
Volume
A 2-pipe-connected buffer vessel is used when the system
volume in the climate system is less than the minimum re-
commended volume for the heat pump.
NIBE S1156Chapter 4 | Pipe connections18