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Standby troubleshooting

🔧 Standby Power Shows as 0W

Some bulbs use very little standby power (often 0.1–0.3 W). Many smart plugs cannot accurately measure loads this small, causing the measurement tool to report 0W.

Why This Happens

Most consumer grade smart plugs have a minimum measurable load of 0.3–0.5 W. Anything below that is rounded down to zero, even though the bulb does consume standby power.

✔️ Troubleshooting Steps

1. Measure Multiple Bulbs in Parallel

If you have more than one identical bulb, connect them in parallel and measure their combined standby power.

Example:

  • Expected standby: ~0.2 W per bulb
  • With 4 bulbs: ~0.8 W total → usually measurable

Make sure to have a group in HA that turns on/off all bulbs simultaneously during measurement. In the measure tool wizard select yes when asked Are you measuring multiple lights?. On the next screen, enter the number of bulbs you are measuring.

2. Add a Dummy Load

Some smart plugs require a stable resistive load before they can measure accurately. Use a small incandescent bulb (e.g., 25–40 W) as a dummy load on the same circuit. An oven bulb is a good choice since it uses little power and is easy to find.

Warning

Do not use an LED bulb as a dummy load. LED bulbs are not stable resistive loads and will cause fluctuating or inaccurate readings.

3. Try a Different Smart Plug / Energy Meter

Not all smart meters can measure sub-watt loads. If possible, try another brand or model known for decent low-load accuracy.

Examples:

  • Good: many Tasmota-based plugs, Shelly Plug Gen3, Blitzwolf/Nous plugs
  • Less accurate: older Shelly Plug S, many Tuya-based plugs below 0.5 W

4. Standby Is Too Low to Measure

If none of the above methods help, the bulb’s standby consumption is likely below the accuracy threshold of your meter. In that case the measurement tool cannot determine a reliable value.

You may manually set a fallback estimate (e.g., 0.2 W), but actual measurement is always preferred when possible. When doing this please note this in the PR description when submitting your measurements.