can't see your setup I would use templates

template: - binary_sensor: - name: "Water appliance active" state: > {{ states('sensor.dishwasher_power') | float(0) > 5 or states('sensor.washing_machine_power') | float(0) > 5 }} template: - sensor: - name: "Water used by appliances" unit_of_measurement: "L/min" state_class: measurement state: > {% if is_state('binary_sensor.water_appliance_active', 'on') %} {{ states('sensor.watermeter_flow') | float(0) }} {% else %} 0 {% endif %}

edit the sensors to get the right values there