Set outside temperature

The Set outside temperature action provides an outside temperature to your thermostat. If your thermostat cannot display an outside temperature and does not support outside temperature correction (OTC), this has no effect. Not all thermostats can display the full supported range.

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 set the outside temperature 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. From the search box, search for and select OpenTherm Gateway: Set outside temperature.
  6. Enter the Gateway ID and the Temperature.
  7. Select Save.

This action does not support targets. In the UI, you are not prompted to choose an area, device, entity, or label.

Options in the UI

Gateway ID (Required)

The ID of the OpenTherm Gateway, as specified during configuration.

Temperature (Required)

The temperature to provide to the thermostat. Values between -40.0 and 64.0 are accepted, but not all thermostats can display the full range. Any value above 64.0 clears a previously configured value (suggestion: 99).

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 opentherm_gw.set_outside_temperature. A basic example looks like this:

ActionActions are used in several places in Home Assistant. As part of a script or automation, actions define what is going to happen once a trigger is activated. In scripts, an action is called *sequence*. [Learn more]
action: opentherm_gw.set_outside_temperature
data:
  gateway_id: opentherm_gateway
  temperature: 12.5

This provides an outside temperature of 12.5 degrees to the thermostat.

Options in YAML

gateway_id string Required

The ID of the OpenTherm Gateway, as specified during configuration.

temperature float Required

The temperature to provide to the thermostat. Values between -40.0 and 64.0 are accepted, but not all thermostats can display the full range. Any value above 64.0 clears a previously configured value (suggestion: 99).

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.

Tip

You don’t need to edit YAML to use these examples. Copy a YAML snippet from this page, open the automation editor in Home Assistant, and press Ctrl+V (or Cmd+V on Mac). Home Assistant automatically converts the pasted YAML into the visual editor format, whether it’s a full automation, a single trigger, a condition, or an action.

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.

Tip

AI assistants like ChatGPT or Claude can also explain actions or suggest the right one when you describe what you want in plain language.

Related actions

These actions work well alongside this one: