Simple sensor list config is throwing an error?

Configuration
1

Config checker in dev tools is throwing an error, but why?

hvac_logic_heating:

  sensor:

    # ROOM TEMP SENSOR MANAGEMENT
    - platform: min_max      
      name: room_temp_sensors_avg
      round_digits: 1
      type: mean 
      entity_ids:
        - sensor.trv_7922_temperature
        - sensor.trv_8005_temperature
        - sensor.trv_8008_temperature
        - sensor.trv_8206_temperature

    - platform: min_max      
      name: room_temp_sensors_max
      round_digits: 1
      type: max 
      entity_ids:
        - sensor.trv_7922_temperature
        - sensor.trv_8005_temperature
        - sensor.trv_8008_temperature
        - sensor.trv_8206_temperature
      
    - platform: template
        sensors: #-- THIS IS THE LINE GENERATING THE ERROR
          room_temp_avg:  
            value_template: "{{ '%.0f' | format(states('sensor.room_temp_sensors_avg')  }}"

error:

Error loading /config/configuration.yaml: mapping values are not allowed here
in "/config/packages/hvac/logic/heating.yaml", line 27, column 16
2

Never mind. schoolboy spacing format error.