In 2-pipe applications, the thermostat controls a valve in heating/cooling mode with changeover (automatically or manually), heating only, or cooling only (factory setting, P02 = 2).
On/Off control
Control sequence
On/Off control output
The diagrams below show the control sequence for On/Off control.
Heating mode | Cooling mode |
|
|
YHC | Control command "Valve" |
SDH | Hysteresis "Heating" (P43) |
SDC | Hysteresis "Cooling" (P44) |
T[°C] | Room temperature |
w | Room temperature setpoint |
Modulating control:
3-position or DC 0…10 V
Control sequence modulating output
The diagrams below show the control sequence for modulating PI control.
Heating mode | Cooling mode |
|
|
YHC | Control command "Valve" |
XpH | Proportional band "Heating" (P43) |
XpC | Proportional band "Cooling" (P44) |
T[°C] | Room temperature |
w | Room temperature setpoint |
Note
The diagrams only show the PI thermostat’s proportional part.
For setting sequence and control outputs, see Sequence overview (setting via P02) and Control outputs.