Automating Your Laundry Room With Smart Plugs

Laundry sitting wet in the washer for hours because you forgot about it, that is a universal experience. The fix is embarrassingly simple: a smart plug with power monitoring. It costs $15, takes 5 minutes to set up, and sends you a notification the moment your washer or dryer finishes.

Here is exactly how it works and how to set it up.

The Concept

Your washer draws significant power while running (300-500 watts) and almost nothing when idle (1-3 watts). A smart plug with energy monitoring tracks that power draw in real time. When the power drops below a threshold for a sustained period, the cycle is done. You fire a notification.

The Automation

In Home Assistant, create an automation with two triggers:

Washer started: Power goes above 10 watts for at least 2 minutes (avoids false triggers from door light or standby fluctuations).

Washer finished: Power drops below 5 watts for at least 3 minutes (some washers have brief pauses between cycles, so the sustained check avoids premature notifications).

The notification action is up to you. A push notification through the Home Assistant Companion app, a single blue flash of the kitchen lights as a visual cue, and a message to a family Telegram group all work. Pick whatever actually gets your attention.

The Helper Entity Trick

For a cleaner setup, create an input_select helper with states: "Idle", "Running", and "Done." Update this helper based on power thresholds. Then your notifications and dashboard displays can reference the washer state directly instead of raw power values. Your dashboard shows "Washer: Running" instead of "Washer plug: 347W."