Instantaneous Heating Water Heater - Viessmann VITOCAL WPR 300 Service Instructions Manual

DHW cylinders
(cont.)
Forced heat transfer
Minimum compressor runtimes
increase the efficiency and protect the
components of the heat pump. Sur-
plus heat can be transferred to the
consumers, as soon as they receive a
"transfer signal" from the control unit.
Parameter "Excess reaction" (600F)
determines whether and under what
conditions the DHW cylinder absorbs
the surplus heat.

Instantaneous heating water heater

An electric instantaneous heating water heater can be integrated in the heating
water flow as an auxiliary heat source. Control via the heat pump control unit is
enabled with parameter "Inst.htg.water heat" (7900).
The system operator can enable the
instantaneous heating water heater
separately for central heating
("Electric heating", 7902) or for
DHW heating ("DHW with e heat-
ing", 6015).
If one of the following conditions is
met, the heat pump control unit starts
the instantaneous heating water hea-
ter:
Function description
The forced heat transfer also ends
when "Max. temp" (6006) is reached.
& A direct heat demand is present, e.
g. from a consumer for frost protec-
tion.
& The actual value for "E heating
threshold" (730E) exceeds the set
value. Following matching of the set
flow temperature in the secondary
circuit, this actual value is not calcu-
lated in the "Heater rod delay"
(7905). This occurs e.g. after chan-
ging the operating mode "Stan-
dard"/"Reduced" or after switching
"Central heating"/"DHW heating".
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