Viessmann VITOLIGNO 300-P Service Instructions Manual page 120

Function description
Control functions
Control sequence
Code "55:1", cylinder heating
Systems without heating water buffer
cylinder
The DHW cylinder goes cold (set value
−2.5 K; change via coding address "59"):
■ The set boiler water temperature is
adjusted 15 K higher than the set DHW
temperature (adjustable via coding
address "60").
■ Pump on:
– Starting the circulation pump for cyl-
inder heating subject to the boiler
water temperature (code "61:0"):
The circulation pump starts when
the boiler water temperature is 7 K
higher than the DHW temperature.
– Immediate start of the circulation
pump for cylinder heating (code
"61:1").
The DHW cylinder is hot (set value
+2.5 K):
■ The set boiler water temperature is
returned to the weather-compensated
set value.
■ Pump run-on:
The circulation pump runs on after cyl-
inder heating until one of the following
criteria is met:
– The differential between the boiler
water and the DHW temperature is
less than 7 K.
– The weather-compensated set flow
temperature has been reached.
– The set DHW temperature is excee-
ded by 5 K.
– The set max. run-on time has been
reached (coding address "62").
■ Without pump run-on (code "62:0")
120
(cont.)
Systems with heating water buffer
cylinder
The circulation pump for cylinder heating
starts when the differential between the
buffer cylinder temperature (top sensor)
and the actual cylinder temperature
exceeds 8 K (coding address "84").
The circulation pump for cylinder heating
stops when the boiler water/buffer cylin-
der temperature (top sensor) falls below
the actual cylinder temperature by the
differential comprising the values of cod-
ing addresses "84" and "85"
Code "55:2", adaptive cylinder heat-
ing
With adaptive cylinder heating, the
speed of the temperature rise during
DHW heating is taken into account.
The DHW cylinder goes cold (set value
−2.5 K; change via coding address "59"):
■ The set boiler water temperature is
adjusted 15 K higher than the set DHW
temperature (adjustable via coding
address "60").
■ Pump on:
– Starting the circulation pump for cyl-
inder heating subject to the boiler
water temperature (code "61:0"):
The circulation pump starts when
the boiler water temperature is 7 K
higher than the DHW temperature.
– Immediate start of the circulation
pump for cylinder heating (code
"61:1").