Heating and cooling

In 4-pipe applications, the thermostat controls 2 valves in heating and cooling mode, heating/cooling mode by manual selection. Heating and cooling mode (P02 = 4) is factory-set.

4-pipe application with manual changeover

The heating or cooling output can be released via operating mode button if P02 is set to Manual (P02 = 3).

On/Off control

The diagrams below show the control sequence for On/Off control.

Heating and cooling mode (P02 = 4)

Heating mode with manual selection (P02 = 3)

Cooling mode with manual selection (P02 = 3)

T[°C]     Room temperature

YH       Control command "Valve"
            (heating)

w          Room temperature setpoint

YC       Control command "Valve"
            (cooling)

Xdz        Dead zone (P42)

SDH      Switching differential "Heating"
            (P40)

SDC      Switching differential "Cooling"
            (P41)