7
■ The output of type BW 351.A can be
supplemented with a stage 2 heat
pump (type BWS).
■ Using the conversion kit (accessory),
the brine/water heat pump type BW
can be converted into a water/water
heat pump. A separate well circuit pro-
vides the primary circuit with heating
energy via a separating heat
exchanger (accessory). The compo-
nents of the well and primary circuit
are switched by the heat pump control
unit.
Type BWS 351.A18 (heat pump stage 2)
■ Heat pump stage 2 has a separate
refrigerant circuit with refrigerant cir-
cuit controller, but no separate heat
pump control unit. Stage 2 is switched
via the heat pump control unit of
stage 1.
■ Depending on the hydraulic connec-
tion, the heat pump stage 2 can be
used both for central heating and for
DHW heating. Correspondingly, a
separate secondary pump and circu-
lation pump for cylinder heating (both
accessories) are required for the
stage 2 heat pump.
■ With the 2-stage version, either a sep-
arate primary pump can be used for
both stages, or a common primary
pump can be used on the primary side.
Irrespective of this, the flow and return
temperature sensors are installed in
the primary circuit at the common flow
and return.
■ The stage 2 heat pump must be instal-
led to the left of the stage 1 heat pump.
Preparing for installation
Product information
(cont.)
5546 267 GB
Installation
