Water heater operation mode changed

The Water heater operation mode changed trigger fires when a water heater 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] changes to one of the operation modes you select. Use it when you want an automation to react to a specific mode, like switching related devices to an energy-saving setup when the water heater changes to Eco mode.

When you target more than one water heater, the Trigger when option controls whether the automation runs for each matching change, only for the first one, or only after all targeted water heaters reach the selected mode.

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 Water heater operation mode changed 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 water heater is in, or select a device, a specific entity, a floor, or a label.
5. From the triggers shown for that target, select Water heater operation mode changed.
6. Under Operation mode, select one or more modes to watch for. Only modes supported by the targeted water heater are shown.
7. Under Trigger when (see Behavior), pick Each, First, or All.
8. Under For at least, enter how long the water heater must stay in the selected mode before the trigger fires.
9. 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, Water heater operation mode changed is referred to as water_heater.operation_mode_changed. A basic example looks like this:

trigger: water_heater.operation_mode_changed
target:
  entity_id: water_heater.utility_room
options:
  operation_mode: eco

This fires when water_heater.utility_room changes to eco mode.

To watch for more than one mode:

trigger: water_heater.operation_mode_changed
target:
  entity_id: water_heater.utility_room
options:
  operation_mode:
    - eco
    - heat_pump
  behavior: first
  for: "00:05:00"

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 water_heater entity behind that target.

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

• The available operation modes depend on the water heater. Home Assistant only shows modes that the targeted entity supports.
• This trigger fires when the mode changes to one of the selected modes. It does not fire when the water heater leaves that mode.
• unavailable and unknown are not offered as selectable modes.
• To react when the water heater simply turns on or off, use Water heater turned on or Water heater turned off.

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: send a notification when the water heater enters boost mode

When the water heater changes to a high-demand or boost-style mode, send a notification so you know hot water recovery is being prioritized.

• Trigger: Water heater operation mode changed
  • Target: Utility room water heater
  • Operation mode: performance
• Action: Send a notification message
  • Target: My Device (notify.my_device)

alias: "Notify when water heater enters performance mode"
triggers:
  - trigger: water_heater.operation_mode_changed
    target:
      entity_id: water_heater.utility_room
    options:
      operation_mode: performance
actions:
  - action: notify.send_message
    target:
      entity_id: notify.my_device
    data:
      message: "The water heater switched to performance mode."

Automation: lower the recirculation pump when the first water heater enters Eco mode

When the first targeted water heater changes to Eco mode, reduce the recirculation pump speed to save energy.

• Trigger: Water heater operation mode changed
  • Target: Water heaters with the energy label
  • Operation mode: eco
  • Trigger when: First
  • For at least: 00:05:00
• Action: Turn on switch

alias: "Lower recirculation pump in Eco mode"
triggers:
  - trigger: water_heater.operation_mode_changed
    target:
      label_id: energy_water_heaters
    options:
      operation_mode: eco
      behavior: first
      for: "00:05:00"
actions:
  - action: switch.turn_on
    target:
      entity_id: switch.recirculation_pump_low_speed

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:

• Water heater turned on: Triggers after one or more water heaters turn on, regardless of the operation mode.

• Water heater turned off: Triggers after one or more water heaters turn off.