STIEBEL ELTRON LWZ 304 SOL - Economy Settings

ENGLISH
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INSTALLATION
Settings
7.2 Economy settings
The appliance has been set up at the factory to give priority to
providing heating and DHW conveniently under all circumstanc-
es. In doing this, it may occur that more energy than required is
used. The following describes a range of measures you can take to
reduce energy consumption with only small sacrifices to comfort.
Note
Please note that the energy demand of a new building
can be significantly higher in the first two years (drying
out) than the calculated energy demand.
7.2.1 DHW temperature
If the DHW temperature for day mode is set above 45°C, the heat
pump may not be able to complete DHW heating under some cir-
cumstances. In this case, the electric emergency/booster heater
is also started, so the required DHW temperature of up to 55°C
is reached.
To avoid this, you can use the "DHW ECO" function. If the set DHW
temperature is not reached with the heat pump alone, the set DHW
value is adjusted automatically so the electric emergency/booster
heater will not be required.
 Set "DHW ECO" to "ON".
7.2.2 Pasteurisation
To protect against the growth of legionella bacteria, the contents
of the DHW cylinder are heated at adjustable intervals to the tem-
perature selected under the "PASTEURISATION TEMP." parameter
(“SETTINGS/ DHW/ STANDARD SETTING).
When heating DHW in detached houses check whether this func-
tion may possibly be omitted. In such cases, the "PASTEURISATION
T E MP." parameter may be set to 10°C. This value is preset.
There is a risk of legionella bacteria growth if only little DHW is
used. Legionella bacteria are generally only a danger to people
with weakened immune systems.
7.2.3 Heating curve
Adjust the heating curve carefully, as the heat pump efficiency
will be reduced with an increasing flow temperature. See chapter
"Operation/ MAIN MENU/ SETTINGS
/ HEATING" in the operating
instructions.
7.2.4 Electric booster in heating mode
If it is correctly sized, the heat pump should cover the heat demand
by itself, down to an outside temperature of approx. -5°C, if the
DHW demand is not excessive. The electric emergency/booster
heater starts subject to output. However, it may occur that the
electric emergency/booster heater starts even though the heating
output of the heat pump would still be sufficient. To prevent this,
the dual mode point (P78), above which the electric emergency/
booster heater is blocked, should be set to -5°C. The factory
setting is 0°C.
Note
On account of the moisture contained in building materi-
als, new buildings have a higher heat demand than will
be the case one or two years later. It may therefore be
required to set a higher dual mode point.
7.2.5 Summer mode
The summer/winter changeover temperature is factory-set (pa-
rameter "SUMMER MODE" under "HEATING/ STANDARD SETTING",
P49) to 20°C and the "HYST. SUMMER MODE" (P50) to 1K. At an
outside temperature above 21°C, heating stops; heating restarts
if the outside temperature drops below 19°C.
Sample application: If "SUMMER MODE" is set to 13°C and "HYST.
SUMMER MODE" to 3K, then central heating will be blocked at
outside temperatures in excess of 16°C and re-enabled at below
10°C. This significantly reduces the heating runtime.
Note
One condition for the cooling function is that summer
mode has been activated.
7.2.6 Pump cycles
In the "CONTRACTOR" menu under "PUMP CYCLES", you can set
how many times a day the heating circuit pump starts. With the
aid of pump cycles, in winter you can set the pump not to start
while the compressor is blocked (20min). For this purpose, set
"MAXIMUM CYCLES" (P55) to 50 and "OUTSIDE TEMP MAX CYC"
(P56) to 0°C. Below 0 °C, the pump therefore starts no more than
50 times a day.
This stops the electric booster heater being started while the com-
pressor is blocked, although the compressor output should still
be sufficient.
In summer, the pump should start only once a day while the tem-
perature is above the summer/winter changeover temperature
("SUMMER MODE" parameter). For this, "OUTSIDE TEMP MIN CYC"
(P57) must be set to the total of the values "SUMMER MODE" (P49)
and "HYST. SUMMER MODE" (P50).
Note
For solar DHW heating, set the values listed under the
description with "DHW solar temp." for these pump cycle
parameters.
Note
Feedback from the rooms is only available when the heat-
ing circuit pump runs, making this a condition for the
recognition of a heat demand.