Honeywell SDC Service Manual page 205

SDC / DHC
EN2H-0221GE51 R0812
Control mode 4 – Discharge control for heating circuit demand
System hydraulics
a Buffer tank
b Heat generator
As control mode 3, except that the demand from hot-water control
are sent directly to the heat generator.
An active hot-water priority only acts on the heating circuits when
there is no buffer discharge in progress.
See the table below for detailed correlations.
Control mode 5 – Loading control with hot-water switch-over valve
System hydraulics
a Heat generator
Hydraulic Components
c Hot-water tank
b Buffer tank
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