In 2-pipe applications, the thermostat controls a valve in heating/cooling mode with changeover (manually) (factory setting, P02 = 3).

On/Off control

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

Floor heating mode

FCU cooling mode

T[°C]     Room temperature

YH       Control command "Valve"
            (floor heating)

w          Room temperature setpoint

YC       Control command "Valve"
            (FCU cooling)

SDH      Switching differential "Heating"
            (P40)

SDC      Switching differential "Cooling"
            (P41)