Accessory card. An accessory card is required if step controlled additional heat (e.g. external electric boiler) or if shunt controlled additional heat (e.g. wood/oil/gas/pellet boiler), passive/active cooling 2 pipe, passive cooling 2 respectively 4 pipe or if hot water comfort is to be connected to F1345. An accessory card is also required if the ground water pump or external circulation pump is connected to F1345 at the same time that the buzzer alarm is activated.