Humidifier started drying

The Humidifier started drying trigger fires when a humidifier entityAn entity represents a sensor, actor, or function in Home Assistant. Entities are used to monitor physical properties or to control other entities. An entity is usually part of a device or a service. [Learn more] begins actively removing moisture from the air. This typically applies to dehumidifiers and devices with a dehumidification device class that pause once the target humidity is reached and then resume when the air becomes too humid again.

Use this trigger to track dehumidification cycles, send alerts when the air becomes too humid, or coordinate other actions that should happen while the device is actively removing moisture.

When you target more than one humidifier, the Trigger when option controls when it fires.

Using this trigger from the user interface

If you prefer building automations visually, Home Assistant walks you through this trigger step by step. You pick what to watch, tweak a few options, and save. No YAML knowledge required.

To use Humidifier started drying in an automation:

1. Go to Settings > Automations & scenes.
2. Open an existing automation, or select Create automation > Create new automation.
3. In the When section, select Add trigger.
4. Select what you want to monitor. Under By target (see Targets), pick the area your dehumidifier is in (like your basement or bathroom). You can also select a device, a specific entity, or a label.
5. From the triggers shown for that target, select Humidifier started drying.
6. Under Trigger when (see Behavior), pick Each, First, or All to control how the trigger behaves when multiple devices are targeted.
7. Under For at least, set how long the device must be actively drying before the trigger fires. Leave it at zero to fire immediately.
8. Select Save.

Options in the UI

Using this trigger in YAML

If you work directly in YAML, or you want to know exactly what Home Assistant does under the hood, this section has the technical reference. It lists the field names you use in YAML, their types, and which ones are required.

In YAML, Humidifier started drying is referred to as humidifier.started_drying. A basic example looks like this:

trigger: humidifier.started_drying
target:
  entity_id: humidifier.basement_dehumidifier

This fires every time humidifier.basement_dehumidifier starts actively removing moisture from the air.

Options in YAML

YAML sometimes provides additional options for more complex use cases that are not available through the UI.

Targets of the trigger

This trigger requires a target. The target is the object that Home Assistant will watch. You can select a single entityAn entity represents a sensor, actor, or function in Home Assistant. Entities are used to monitor physical properties or to control other entities. An entity is usually part of a device or a service. [Learn more], a device, an area, a floor, or a label as a target, and Home Assistant will watch every matching humidifier entity behind that target.

• Entity: one specific humidifier entity, such as humidifier.living_room.
• Device: every humidifier entity that belongs to a device.
• Area: every humidifier entity in a room or area.
• Floor: every humidifier entity on a floor.
• Label: every humidifier entity that shares a label.

You can also select different target types in one trigger. For example, you can add a specific entity and an area as targets in the same trigger to monitor both of them at once.

Behavior with multiple targets

When you target more than one entity (or select an area, floor, or label that contains several), the Trigger when option controls how the trigger responds:

• Each (any in YAML, default): the trigger fires every time any one of the targeted entities transitions. For example, if you monitor three motion sensors in the living room and someone walks past sensor 1, the automation fires. When they walk past sensor 2 a moment later, it fires again. Every individual event counts.
• First (first in YAML): the trigger fires only on the first transition in the targeted group, then waits until all targeted entities have reset before it fires again. For example, if you monitor the same three motion sensors, the automation fires when the first one picks up movement (someone entered the room). The other two firing afterward are ignored, so you get one notification per “someone walked in” event instead of three.
• All (last in YAML): the trigger fires only after the last targeted entity in the group has fired, meaning all of them are now in the expected state. For example, if you monitor the lights in the living room, bedroom, and hallway, the automation fires only once all three have turned off. This is useful for scenarios like “start the robot vacuum only after every light on the floor is off,” so you know the room is truly empty.

Good to know

• Humidifier started drying fires independently of Humidifier turned on. A dehumidifier can be on but idle (the air is already dry enough), and Humidifier started drying fires only when active drying begins.
• Humidifier started drying is most useful with devices that have the dehumidifier device class, but it also applies to multi-mode devices that can switch between humidifying and drying.

Try it yourself

Ready to test this? Go to Settings > Automations & scenes, create a new automation, and add this trigger. Save the automation, then change the state of the targeted entity to watch the trigger fire on your actual entitiesAn entity represents a sensor, actor, or function in Home Assistant. Entities are used to monitor physical properties or to control other entities. An entity is usually part of a device or a service. [Learn more].

More examples

Real scenarios where this trigger fires in automations and scripts. Copy any example and adapt it to your setup.

Automation: alert when the basement gets too humid

When the basement dehumidifier starts running again, it means the air has become too humid. Send a notification so you can check whether there is a moisture problem that needs attention.

• Trigger: Humidifier started drying
• Target: Basement dehumidifier
• Trigger when: Each
• For at least: 00:05:00
• Action: Send a mobile notification

alias: "Alert when basement dehumidifier starts"
triggers:
  - trigger: humidifier.started_drying
    target:
      entity_id: humidifier.basement_dehumidifier
    options:
      behavior: any
      for: "00:05:00"
actions:
  - action: notify.mobile_app_phone
    data:
      message: "Basement dehumidifier started drying. Humidity may be high."

Automation: close the windows when the dehumidifier kicks in

When the dehumidifier starts drying, close any open motorized windows automatically to prevent more humid air from coming in and making the device work harder. Motorized windows are supported in Home Assistant through integrations like Velux, Somfy, and KNX.

• Trigger: Humidifier started drying
• Target: Basement dehumidifier
• Trigger when: Each
• For at least: 00:00:00
• Action: Cover: Close cover

alias: "Close windows when dehumidifier starts"
triggers:
  - trigger: humidifier.started_drying
    target:
      entity_id: humidifier.basement_dehumidifier
    options:
      behavior: any
      for: "00:00:00"
actions:
  - action: cover.close_cover
    target:
      area_id: basement

Still stuck?

The Home Assistant community is quick to help: join Discord for real-time chat, post on the community forum with the trigger you’re using and what you expected to happen, or share on our subreddit /r/homeassistant.

Related triggers

These triggers work well alongside this one:

• Humidifier turned on: Triggers after one or more humidifiers turn on.

• Humidifier started humidifying: Triggers after one or more humidifiers start actively humidifying.