Wwk 301 Electronic Sol : Connection Of An External Heat Generator; Condensate Drain - STIEBEL ELTRON WWK 221 electronic Bedienung Und Installation

INsTALLATIoN
Installation
10.3 WWK 301 electronic SOL : Connection of an
external heat generator
Material losses
!
Even if an external heat generator is connected, do not
disconnect the appliance from the power supply as oth-
erwise it is not protected against frost and corrosion. The
power supply must not be interrupted even in winter,
when it is possible that DHW heating is only being pro-
vided via the external heat generator.
Material losses
!
The integration of an external heat generator via the "heat
source flow" connection must not result in the application
limits being exceeded (see chapter "Specification / Data
table").
The connected external heat generator cannot be con-
trolled by the appliance. The external heat generator
must be controlled externally. Any possibility of exceed-
ing the maximum permissible DHW temperature in the
cylinder (as given in chapter "Specification/Data table")
must be prevented.
Material losses
!
Carry out all installation work in accordance with regula-
tions. In Germany, to comply with heating system regula-
tions, an external heat generator must be connected with
a diaphragm expansion vessel and a safety valve between
the external heat generator and the DHW cylinder.
External heat generators may only be connected with DHW priority
control. As part of this, the cylinder temperature must be captured
with an electronic temperature sensor with safety low voltage.
The DHW cylinder of the appliance allows the temperature sensor
to be positioned at one of two different heights in the cylinder.
Using the sensor sleeve in the upper third of the cylinder enables
later DHW heating by means of the external heat generator, than
the lower sensor position.
Heating circuit oxygen diffusion
Material losses
!
Avoid open vented heating systems and underfloor
heating systems with plastic pipes that are permeable
to oxygen.
In underfloor heating systems with plastic pipes that are per-
meable to oxygen and in open vented heating systems, oxygen
diffusion may lead to corrosion on the steel components of the
heating system (e.g. on the indirect coil of the DHW cylinder, on
buffer cylinders, steel radiators or steel pipes).
Material losses
!
The products of corrosion (e.g. rusty sludge) can set-
tle in the heating system components, which may re-
sult in a lower output or fault shutdowns due to reduced
cross-sections.
62 | WWK 221-301 electronic
Solar circuit oxygen diffusion
Material losses
!
Avoid open vented solar thermal systems and plastic
pipes which are permeable to oxygen.
With plastic pipes that are permeable to oxygen, oxygen diffusion
can cause corrosion on the steel components of the solar thermal
system (e.g. on the indirect coil of the DHW cylinder).
Water quality in solar circuit
Material losses
!
A glycol-water mixture up to 60 % is permissible for
the solar circuit, provided only dezincification-resistant
metals, glycol-resistant gaskets and diaphragm expan-
sion vessels suitable for glycol are used throughout the
installation.

10.4 Condensate drain

Install a condensate drain hose in order to remove the condensate
which forms.
f Connect the condensate drain bend included in the standard f
delivery to the "Condensate drain" connection.
f Connect a condensate drain hose to the condensate drain f
bend.
A siphon must be installed to prevent aggressive gases from the
sewer entering the appliance. The condensate drain must be in-
stalled with an outlet that opens freely above the siphon.
Material losses
!
Ensure condensate cannot back up.
f Use a condensate drain hose with a diameter great- f
er than the diameter of the condensate drain bend.
f Ensure the condensate drain hose is not kinked. f
f Route the condensate drain hose with a continuous f
fall.
The condensate drain must be open to atmosphere.
f Use a suitable condensate pump if there is insufficient fall. f
Take the building characteristics into account.
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