Water heater target temperature crossed threshold

The Water heater target temperature crossed threshold 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]’s target temperature crosses a threshold. Unlike Water heater target temperature changed, which reacts to any matching landing value, this trigger reacts only at the moment the setpoint crosses into, out of, above, or below a threshold.

Use it when you want to react to the crossing itself, like turning on a recirculation pump once the target temperature is raised past a certain point.

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 target temperature crossed threshold 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 target temperature crossed threshold.
6. Under Threshold type, choose how the setpoint must cross the threshold.
7. If needed, select a fixed number or a supported temperature entity for the threshold.
8. Under Unit, select the temperature unit to use for the comparison when you enter a number.
9. Under Trigger when (see Behavior), pick Each, First, or All.
10. Under For at least, enter how long the water heater must stay beyond the threshold before the trigger fires.
11. 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 target temperature crossed threshold is referred to as water_heater.target_temperature_crossed_threshold. A basic example looks like this:

trigger: water_heater.target_temperature_crossed_threshold
target:
  entity_id: water_heater.utility_room
options:
  threshold:
    type: above
    value:
      number: 55
      unit_of_measurement: "°C"

This fires when the target temperature of water_heater.utility_room crosses above 55°C.

To wait for a sustained change across multiple water heaters:

trigger: water_heater.target_temperature_crossed_threshold
target:
  label_id: upstairs_water_heaters
options:
  threshold:
    type: below
    value:
      number: 48
      unit_of_measurement: "°C"
  behavior: last
  for: "00:10:00"

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

• This trigger watches the target temperature setpoint, not the current measured water temperature.
• It fires only when the setpoint crosses the threshold boundary. It does not keep firing while the setpoint stays beyond the threshold.
• To react to any setpoint change that lands above, below, inside, or outside a range, use Water heater target temperature changed.
• When you use an entity as the threshold, Home Assistant uses that entity’s current value when the crossing happens.

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: start recirculation when the setpoint crosses above 55°C

When the target temperature is raised above 55°C, start the recirculation pump so hot water is available more quickly.

• Trigger: Water heater target temperature crossed threshold
  • Target: Utility room water heater
  • Threshold type: Above (55°C)
• Action: Turn on switch

alias: "Start recirculation after a higher setpoint"
triggers:
  - trigger: water_heater.target_temperature_crossed_threshold
    target:
      entity_id: water_heater.utility_room
    options:
      threshold:
        type: above
        value:
          number: 55
          unit_of_measurement: "°C"
actions:
  - action: switch.turn_on
    target:
      entity_id: switch.hot_water_recirculation

Automation: notify when all targeted water heaters stay below the minimum setpoint

When every targeted water heater has a target temperature below your minimum comfort setting for 10 minutes, send a notification.

• Trigger: Water heater target temperature crossed threshold
  • Target: Upstairs water heaters
  • Threshold type: Below (48°C)
  • Trigger when: All
  • For at least: 00:10:00
• Action: Send a notification message
  • Target: My Device (notify.my_device)

alias: "Warn when all water heaters are set too low"
triggers:
  - trigger: water_heater.target_temperature_crossed_threshold
    target:
      label_id: upstairs_water_heaters
    options:
      threshold:
        type: below
        value:
          number: 48
          unit_of_measurement: "°C"
      behavior: last
      for: "00:10:00"
actions:
  - action: notify.send_message
    target:
      entity_id: notify.my_device
    data:
      message: "All targeted water heaters have stayed below 48°C for 10 minutes."

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 target temperature changed: Triggers after the temperature setpoint of one or more water heaters changes.

• Water heater operation mode changed: Triggers after the operation mode of one or more water heaters changes to a specific mode.