Honeywell SDC Service Manual page 200

Hydraulic Components
Parallel switch-over
Heat balancing
Reset heat balancing
200
Solar priority/parallel switch-over (only with solar control
mode = priority mode)
Operation in hot-water priority mode
If the actual hot-water temperature undershoots the hot-water
setpoint by the set amount, solar priority mode is cancelled until
the hot-water setpoint has been reached.
Example:
Hot-water setpoint is 50°C, set value switch-over: 10 K.
There is no demand for the heat generator until the hot-water
temperature drops below 40°C.
Operation in buffer priority mode
If the actual buffer temperature undershoots the buffer setpoint by
the set amount, solar priority mode is cancelled until the buffer
setpoint has been reached.
Example:
Setpoints at buffer of heating circuits: 45°C
Buffer offset: 10 K
Switch-over set value: 20 K
There is no demand for the heat generator until the buffer
temperature drops below 35°C.
Heat balancing is activated through a parameter setting. The user
can select between flow calculation via the pump runtime and
determination of the flow volume via the pulse signal input of the
device, if such an input is available. Any commercial flow meter
can be connected to the pulse input.
(only if heat balancing is activated)
With this function, the heat balancing counter can be reset when
heat balancing is activated.
SDC / DHC
EN2H-0221GE51 R0812