Set DHW override

Use this action to override the scheduled state of a DHW controller, for example to heat the water now rather than waiting for the next scheduled period. The override can be indefinite, or it can run for a set time after which the controller goes back to following its schedule.

Using this action from the user interface

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

To override the hot water state from an automation or a script:

1. Go to Settings > Automations & scenes.
2. Open an existing automation or script, or select Create automation > Create new automation.
3. If you’re setting up a new automation, add a trigger in the When section. Scripts don’t need a trigger. They run when something else calls them.
4. In the Then do section, select Add action.
5. Select what you want to control. Under By target (see Targets), select the hot water controller you want to override.
6. From the actions shown for that target, select Set DHW override.
7. Set the State and, optionally, a Duration.
8. Select Save.

Options in the UI

Using this action 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, refer to this action as evohome.set_dhw_override. A basic example looks like this:

action: evohome.set_dhw_override
target:
  entity_id: water_heater.dhw_controller
data:
  state: true
  duration: "02:00"

This heats the water for two hours, then lets the controller return to its schedule.

Options in YAML

Targets of the action

This action requires a target. The target is the object of the action. You can point the action at 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, and Home Assistant will run the action on 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 action. For example, you can add a specific entity and an area as targets in the same action to run the action on both of them at once.

Good to know

• Leave the duration empty for a permanent override that stays until you change it. Set a duration for a temporary override that reverts on its own.
• A duration of zero is a special case: the override lasts only until the next scheduled state change.

Try it yourself

Ready to test this? Open Developer tools > Actions, search for this action, fill in the fields, and select Perform action. You see what happens 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] without writing a line of YAML.

More examples

Real scenarios where this action shows up in automations and scripts. Copy any example and adapt it to your setup.

Automation: heat the water when off-peak electricity starts

When your off-peak electricity rate begins, override the hot water on for two hours so it heats up while power is cheaper.

• Trigger: Off-peak tariff starts
• Action: Set DHW override on, for two hours

alias: "Heat water during off-peak hours"
triggers:
  - trigger: state
    entity_id: binary_sensor.off_peak_tariff
    to: "on"
actions:
  - action: evohome.set_dhw_override
    target:
      entity_id: water_heater.dhw_controller
    data:
      state: true
      duration: "02:00"

Still stuck?

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

Related actions

These actions work well alongside this one:

• Set zone override: Overrides a heating zone’s setpoint, either indefinitely or for a set time.

• Set system mode: Sets the Evohome system mode, either indefinitely or for a set time, after which it reverts to Auto.