String to float, Sensor Error.

[Niesel1974]

Hi, getting this error:

Traceback (most recent call last):
File "/usr/src/homeassistant/homeassistant/components/sensor/init.py", line 666, in state
numerical_value = float(value) # type:ignore[arg-type]
ValueError: could not convert string to float: "{ states('sensor.e3dc_external_power') | float | abs }}"

Any idea how to fox this?

BR,

Linus

[MrIceman11]

Hi Linus,

Could you please replace the following block in your sensors.yaml file for testing purposes:

e3dc_external_power:
  friendly_name: E3DC External Power
  unit_of_measurement: W
  value_template: >
    { states('sensor.e3dc_external_power') | float | abs }}

through:

e3dc_external_power_abs:
  friendly_name: E3DC External Power (abs)
  unit_of_measurement: W
  value_template: >
    {{ states('sensor.e3dc_external_power') | float(0) | abs }}

Please let us know if this fixes the error – then we can fix it in the repository if necessary.

[Niesel1974]

Hi, the original error is gone with your change, BUT now i receive the following ERROR:

Error while dispatching event for sensor.e3dc_external_power to <Job track state_reported event sensor.e3dc_external_power HassJobType.Callback <bound method IntegrationSensor._integrate_on_state_report_callback of <entity sensor.e3dc_external_power=unknown

Is that due to the changed name _abs? Do I need to fix the name somewherr else now as well?

BR,

Linus

[RudolphMathias]

Hi, I had the same problem and it caused 2025.8.0 to not start properly.
The fix almost worked for me, but I also had to..

add device_class: power to the above block
and remove the following block:

    # - platform: integration
    #   source: sensor.e3dc_wallbox_power
    #   name: E3DC Wallbox Power
    #   unit_prefix: k
    #   round: 2
    #   method: left

Unfortunately there were no logs to what the problem was. For what it's worth: It always looked like the config loading at startup would get stuck in an endless loop.

[Heideachim]

The ValueError: could not convert string to float: "{ states('sensor.e3dc_external_power') | float(0) | abs }}" is NOT resolved by changing "float" to "float(0)".
This error is a direct consequence of the exception: ValueError: Sensor sensor.e3dc_external_power has device class 'power', state class 'None' unit 'W' and suggested precision 'None' thus indicating it has a numeric value; however, it has the non-numeric value: '{ states('sensor.e3dc_external_power') | float(0) | abs }}' (<class 'str'>)

This doesn't seem to be a big problem, since the overall error message indicates that this only happens one time during start-up. I had to restart HA to get the error in the log files. Error running job: <Job onetime listen homeassistant_start <function _async_at_core_state.<locals>._matched_event at 0xffff7a914e00> HassJobType.Callback <_OneTimeListener homeassistant.helpers.start:<function _async_at_core_state.<locals>._matched_event at 0xffff7a914e00>>>