STIEBEL ELTRON LWZ 404 SOL User Manual

OPERATION
Operation
14 | LWZ304-404 SOL www.stiebel-eltron.com
Cooling and solar
Under parameter “SOLAR” qualified contractors can use param-
eter “PRIORITY SOLAR” to select the priority for cooling oper-
ation if a solar thermal system is connected. Possible settings
are “Priority solar”, “Cooling” and the time-controlled setting via
“Cooling time”. This programs the period for cooling. If “Priority
solar” has been selected, cooling will not be enabled for as long
as the solar starting conditions are met and the maximum system
temperatures have not been reached. With “Priority cooling”, the
solar overload function and collector protection are disabled. The
solar start conditions are checked as soon as cooling ends.
 Enable cooling mode for the required heating circuits by set-
ting parameter “COOLING MODE” (“OFF”/ “ON”).
 ROOM TEMPERATURES HC1
 ROOM TEMPERATURE DAY HC1
 ROOM TEMP. NIGHT HC1
 ROOM TEMP. STANDBY HC1
 ROOM TEMPERATURE HC1
Cooling is only possible in conjunction with a buffer cylinder or
low loss header. To allow the appliance to cool, you must set
the “COOLING MODE” parameter to the value “ON”. Refer to your
qualified contractor for the required adjustments.
Cooling is enabled when the appliance is in summer mode and the
outside temperature exceeds the set room temperature for heating
by 3 K for 2 hours. If the room temperature is then higher than the
set room temperature for cooling by the amount set in the “HYST.
ROOM TEMP.” parameter, cooling will be prepared. The display
shows a snowflake. The circulation pump starts, the three-way
valve changes over to the heating circuit and the “cooling” output
is activated in order to, for example, open the thermostatic valves
in the rooms to be cooled.
By selecting a set room temperature you can influence when the
appliance starts its cooling operation.
 ROOM TEMPERATURES HC2
See chapter “ROOM TEMPERATURES HC1”.
 COOLING MODE HC1
 COOLING MODE HC1
OFF
ON
 COOLING SYSTEM HC1
AREA COOLING Code-protected
FAN COOLING Code-protected
 HC TEMP. COOLING HC1 Code-protected
 HYST. ROOM TEMP. HC1 Code-protected
 COOLING MODE HC2
See chapter “COOLING MODE HC1”.
Cooling and DHW heating
Cooling mode is interrupted as soon as a DHW demand is issued,
and DHW heating commences.
 SOLAR
 SOLAR ACTIVATION Direct line: P80
OFF
ON
 TEMP. DIFFERENTIAL Direct line: P81
 DHW COMPRESSOR DELAY Direct line: P82
 DHW SOLAR TEMP. Direct line: P83
If you have connected a solar thermal system, you will find all the
parameters here which have to be specified for solar mode. In
solar mode, the appliance is backed up by the solar heat exchanger
for DHW heating and central heating.
 SOLAR ACTIVATION
If you want to enable solar mode, set the value in parameter
“SOLAR ACTIVATION” to 1.
 TEMP. DIFFERENTIAL
With the aid of this parameter, also known as solar differential
temperature, you define a temperature that is used as the thresh-
old for starting and stopping the solar circuit pump.
The solar circuit pump starts if the collector temperature is high-
er than the return temperature by the “TEMP. DIFFERENTIAL” +
“SOLAR HYSTERESIS”. The solar circuit pump stops if the collector
temperature is only “TEMP. DIFFERENTIAL” – “SOLAR HYSTERESIS”
above the return temperature. The parameter “SOLAR HYSTERE-
SIS” is set by the qualified contractor.
Ensure that the stop point is not below the return temperature.
That can be the case if the hysteresis has been set above the tem-
perature differential. The greater the value of the solar differential
temperature, the later the solar circuit pump starts when the sun
comes out. At the same time, the risk of heat loss from the cyl-
inder is reduced. If heat were lost from the cylinder, the thermal
energy would flow in the opposite direction, i.e. water that had
already been heated would be cooled down because insolation
was still too low.
 DHW COMPRESSOR DELAY
When the solar circuit pump runs, the compressor is blocked for
the period defined here. DHW is only heated with solar energy
during this time.
 DHW SOLAR TEMP.
If the DHW cylinder has been heated up, the set flow temperature
has been reached and the collector temperature remains high,
the DHW cylinder can be heated up to a higher temperature to
store solar energy. Set the temperature to which the DHW cylinder
should be heated here.
WARNING Burns
Parameter “DHW SOLAR TEMP.” should only be set high-
er than 60 °C if suitable measures have been taken to
provide protection against scalding. There is a risk of
scalding at outlet temperatures in excess of 43 °C.
If you want to use the solar function, your qualified contractor
should set the following values:

STIEBEL ELTRON LWZ 404 SOL Specifications

General

Brand	STIEBEL ELTRON
Model	LWZ 404 SOL
Category	Fan
Language	English