---
title: "MQTT HVAC"
description: "Instructions on how to integrate MQTT HVAC into Home Assistant."
ha_category:
  - Climate
ha_release: 0.55
ha_iot_class: Local Polling
ha_domain: mqtt
---

The `mqtt` climate platform lets you control your MQTT enabled HVAC devices.

## Configuration

<a id='new_format'></a>

To enable this climate platform in your installation, first add the following to your `configuration.yaml` file:

```yaml
# Example configuration.yaml entry
mqtt:
  climate:
    - name: Study
      mode_command_topic: "study/ac/mode/set"
```

{% configuration %}
action_template:
  description: A template to render the value received on the `action_topic` with.
  required: false
  type: template
action_topic:
  description: >-
    The MQTT topic to subscribe for changes of the current action. If this is set, the climate graph uses the value received as data source.
    Valid values: `off`, `heating`, `cooling`, `drying`, `idle`, `fan`.
  required: false
  type: string
aux_command_topic:
  description: The MQTT topic to publish commands to switch auxiliary heat.
  required: false
  type: string
aux_state_template:
  description: A template to render the value received on the `aux_state_topic` with.
  required: false
  type: template
aux_state_topic:
  description: The MQTT topic to subscribe for changes of the auxiliary heat mode. If this is not set, the auxiliary heat mode works in optimistic mode (see below).
  required: false
  type: string
availability:
  description: A list of MQTT topics subscribed to receive availability (online/offline) updates. Must not be used together with `availability_topic`.
  required: false
  type: list
  keys:
    payload_available:
      description: The payload that represents the available state.
      required: false
      type: string
      default: online
    payload_not_available:
      description: The payload that represents the unavailable state.
      required: false
      type: string
      default: offline
    topic:
      description: An MQTT topic subscribed to receive availability (online/offline) updates.
      required: true
      type: string
    value_template:
      description: "Defines a [template](/docs/configuration/templating/#using-templates-with-the-mqtt-integration) to extract device's availability from the `topic`. To determine the devices's availability result of this template will be compared to `payload_available` and `payload_not_available`."
      required: false
      type: template
availability_mode:
  description: When `availability` is configured, this controls the conditions needed to set the entity to `available`. Valid entries are `all`, `any`, and `latest`. If set to `all`, `payload_available` must be received on all configured availability topics before the entity is marked as online. If set to `any`, `payload_available` must be received on at least one configured availability topic before the entity is marked as online. If set to `latest`, the last `payload_available` or `payload_not_available` received on any configured availability topic controls the availability.
  required: false
  type: string
  default: latest
availability_template:
  description: "Defines a [template](/docs/configuration/templating/#using-templates-with-the-mqtt-integration) to extract device's availability from the `availability_topic`. To determine the devices's availability result of this template will be compared to `payload_available` and `payload_not_available`."
  required: false
  type: template
availability_topic:
  description: The MQTT topic subscribed to receive availability (online/offline) updates. Must not be used together with `availability`.
  required: false
  type: string
current_humidity_template:
  description: A template with which the value received on `current_humidity_topic` will be rendered.
  required: false
  type: template
current_humidity_topic:
  description: The MQTT topic on which to listen for the current humidity. A `"None"` value received will reset the current temperature. Empty values (`'''`) will be ignored. 
  required: false
  type: string
current_temperature_template:
  description: A template with which the value received on `current_temperature_topic` will be rendered.
  required: false
  type: template
current_temperature_topic:
  description: The MQTT topic on which to listen for the current temperature. A `"None"` value received will reset the current humidity. Empty values (`'''`) will be ignored.
  required: false
  type: string
device:
  description: 'Information about the device this HVAC device is a part of to tie it into the [device registry](https://developers.home-assistant.io/docs/en/device_registry_index.html). Only works through [MQTT discovery](/integrations/mqtt/#mqtt-discovery) and when [`unique_id`](#unique_id) is set. At least one of identifiers or connections must be present to identify the device.'
  required: false
  type: map
  keys:
    configuration_url:
      description: 'A link to the webpage that can manage the configuration of this device. Can be either an HTTP or HTTPS link.'
      required: false
      type: string
    connections:
      description: 'A list of connections of the device to the outside world as a list of tuples `[connection_type, connection_identifier]`. For example the MAC address of a network interface: `"connections": [["mac", "02:5b:26:a8:dc:12"]]`.'
      required: false
      type: list
    hw_version:
      description: The hardware version of the device.
      required: false
      type: string
    identifiers:
      description: 'A list of IDs that uniquely identify the device. For example a serial number.'
      required: false
      type: [list, string]
    manufacturer:
      description: 'The manufacturer of the device.'
      required: false
      type: string
    model:
      description: 'The model of the device.'
      required: false
      type: string
    name:
      description: 'The name of the device.'
      required: false
      type: string
    suggested_area:
      description: 'Suggest an area if the device isn’t in one yet.'
      required: false
      type: string
    sw_version:
      description: 'The firmware version of the device.'
      required: false
      type: string
    via_device:
      description: 'Identifier of a device that routes messages between this device and Home Assistant. Examples of such devices are hubs, or parent devices of a sub-device. This is used to show device topology in Home Assistant.'
      required: false
      type: string
enabled_by_default:
  description: Flag which defines if the entity should be enabled when first added.
  required: false
  type: boolean
  default: true
encoding:
  description: The encoding of the payloads received and published messages. Set to `""` to disable decoding of incoming payload.
  required: false
  type: string
  default: "utf-8"
entity_category:
  description: The [category](https://developers.home-assistant.io/docs/core/entity#generic-properties) of the entity.
  required: false
  type: string
  default: None
fan_mode_command_template:
  description: A template to render the value sent to the `fan_mode_command_topic` with.
  required: false
  type: template
fan_mode_command_topic:
  description: The MQTT topic to publish commands to change the fan mode.
  required: false
  type: string
fan_mode_state_template:
  description: A template to render the value received on the `fan_mode_state_topic` with.
  required: false
  type: template
fan_mode_state_topic:
  description: The MQTT topic to subscribe for changes of the HVAC fan mode. If this is not set, the fan mode works in optimistic mode (see below).
  required: false
  type: string
fan_modes:
  description: A list of supported fan modes.
  required: false
  default: ['auto', 'low', 'medium', 'high']
  type: list
initial:
  description: Set the initial target temperature.
  required: false
  type: integer
  default: 21
icon:
  description: "[Icon](/docs/configuration/customizing-devices/#icon) for the entity."
  required: false
  type: icon
json_attributes_template:
  description: "Defines a [template](/docs/configuration/templating/#using-templates-with-the-mqtt-integration) to extract the JSON dictionary from messages received on the `json_attributes_topic`. Usage example can be found in [MQTT sensor](/integrations/sensor.mqtt/#json-attributes-template-configuration) documentation."
  required: false
  type: template
json_attributes_topic:
  description: The MQTT topic subscribed to receive a JSON dictionary payload and then set as sensor attributes. Usage example can be found in [MQTT sensor](/integrations/sensor.mqtt/#json-attributes-topic-configuration) documentation.
  required: false
  type: string
max_humidity:
  description: The minimum target humidity percentage that can be set.
  required: false
  type: integer
  default: 99
max_temp:
  description: Maximum set point available.
  type: float
  required: false
min_humidity:
  description: The maximum target humidity percentage that can be set.
  required: false
  type: integer
  default: 30
min_temp:
  description: Minimum set point available.
  type: float
  required: false
mode_command_template:
  description: A template to render the value sent to the `mode_command_topic` with.
  required: false
  type: template
mode_command_topic:
  description: The MQTT topic to publish commands to change the HVAC operation mode. Use with `mode_command_template` if you only want to publish the power state.
  required: false
  type: string
mode_state_template:
  description: A template to render the value received on the `mode_state_topic` with.
  required: false
  type: template
mode_state_topic:
  description: The MQTT topic to subscribe for changes of the HVAC operation mode. If this is not set, the operation mode works in optimistic mode (see below).
  required: false
  type: string
modes:
  description: A list of supported modes. Needs to be a subset of the default values.
  required: false
  default: ['auto', 'off', 'cool', 'heat', 'dry', 'fan_only']
  type: list
name:
  description: The name of the HVAC.
  required: false
  type: string
  default: MQTT HVAC
object_id:
  description: Used instead of `name` for automatic generation of `entity_id`
  required: false
  type: string
optimistic:
  description: Flag that defines if the climate works in optimistic mode
  required: false
  type: boolean
  default: "`true` if no state topic defined, else `false`."
payload_available:
  description: The payload that represents the available state.
  required: false
  type: string
  default: online
payload_not_available:
  description: The payload that represents the unavailable state.
  required: false
  type: string
  default: offline
payload_off:
  description: The payload that represents disabled state.
  required: false
  type: string
  default: "OFF"
payload_on:
  description: The payload that represents enabled state.
  required: false
  type: string
  default: "ON"
precision:
  description: The desired precision for this device. Can be used to match your actual thermostat's precision. Supported values are `0.1`, `0.5` and `1.0`.
  required: false
  type: float
  default: 0.1 for Celsius and 1.0 for Fahrenheit.
preset_mode_command_template:
  description: Defines a [template](/docs/configuration/templating/#using-templates-with-the-mqtt-integration) to generate the payload to send to `preset_mode_command_topic`.
  required: false
  type: template
preset_mode_command_topic:
  description: The MQTT topic to publish commands to change the preset mode.
  required: false
  type: string
preset_mode_state_topic:
  description: The MQTT topic subscribed to receive climate speed based on presets. When preset 'none' is received or `None` the `preset_mode` will be reset.
  required: false
  type: string
preset_mode_value_template:
  description: Defines a [template](/docs/configuration/templating/#using-templates-with-the-mqtt-integration) to extract the `preset_mode` value from the payload received on `preset_mode_state_topic`.
  required: false
  type: template
preset_modes:
  description: List of preset modes this climate is supporting. Common examples include `eco`, `away`, `boost`, `comfort`, `home`, `sleep` and `activity`.
  required: false
  type: [list]
  default: []
qos:
  description: The maximum QoS level to be used when receiving and publishing messages.
  required: false
  type: integer
  default: 0
retain:
  description: Defines if published messages should have the retain flag set.
  required: false
  type: boolean
  default: false
swing_mode_command_template:
  description: A template to render the value sent to the `swing_mode_command_topic` with.
  required: false
  type: template
swing_mode_command_topic:
  description: The MQTT topic to publish commands to change the swing mode.
  required: false
  type: string
swing_mode_state_template:
  description: A template to render the value received on the `swing_mode_state_topic` with.
  required: false
  type: template
swing_mode_state_topic:
  description: The MQTT topic to subscribe for changes of the HVAC swing mode. If this is not set, the swing mode works in optimistic mode (see below).
  required: false
  type: string
swing_modes:
  description: A list of supported swing modes.
  required: false
  default: ['on', 'off']
  type: list
target_humidity_command_template:
  description: Defines a [template](/docs/configuration/templating/#using-templates-with-the-mqtt-integration) to generate the payload to send to `target_humidity_command_topic`.
  required: false
  type: template
target_humidity_command_topic:
  description: The MQTT topic to publish commands to change the target humidity.
  required: false
  type: string
target_humidity_state_topic:
  description: The MQTT topic subscribed to receive the target humidity. If this is not set, the target humidity works in optimistic mode (see below). A `"None"` value received will reset the target humidity. Empty values (`'''`) will be ignored.
  required: false
  type: string
target_humidity_state_template:
  description: Defines a [template](/docs/configuration/templating/#using-templates-with-the-mqtt-integration) to extract a value for the climate `target_humidity` state.
  required: false
  type: template
temperature_command_template:
  description: A template to render the value sent to the `temperature_command_topic` with.
  required: false
  type: template
temperature_command_topic:
  description: The MQTT topic to publish commands to change the target temperature.
  required: false
  type: string
temperature_high_command_template:
  description: A template to render the value sent to the `temperature_high_command_topic` with.
  required: false
  type: template
temperature_high_command_topic:
  description: The MQTT topic to publish commands to change the high target temperature.
  required: false
  type: string
temperature_high_state_template:
  description: A template to render the value received on the `temperature_high_state_topic` with. A `"None"` value received will reset the temperature high set point. Empty values (`'''`) will be ignored.
  required: false
  type: template
temperature_high_state_topic:
  description: The MQTT topic to subscribe for changes in the target high temperature. If this is not set, the target high temperature works in optimistic mode (see below).
  required: false
  type: string
temperature_low_command_template:
  description: A template to render the value sent to the `temperature_low_command_topic` with.
  required: false
  type: template
temperature_low_command_topic:
  description: The MQTT topic to publish commands to change the target low temperature.
  required: false
  type: string
temperature_low_state_template:
  description: A template to render the value received on the `temperature_low_state_topic` with. A `"None"` value received will reset the temperature low set point. Empty values (`'''`) will be ignored.
  required: false
  type: template
temperature_low_state_topic:
  description: The MQTT topic to subscribe for changes in the target low temperature. If this is not set, the target low temperature works in optimistic mode (see below).
  required: false
  type: string
temperature_state_template:
  description: A template to render the value received on the `temperature_state_topic` with.
  required: false
  type: template
temperature_state_topic:
  description: The MQTT topic to subscribe for changes in the target temperature. If this is not set, the target temperature works in optimistic mode (see below). A `"None"` value received will reset the temperature set point. Empty values (`'''`) will be ignored.
  required: false
  type: string
temperature_unit:
  description: Defines the temperature unit of the device, `C` or `F`. If this is not set, the temperature unit is set to the system temperature unit.
  required: false
  type: string
temp_step:
  description: Step size for temperature set point.
  type: float
  required: false
  default: 1
unique_id:
   description: An ID that uniquely identifies this HVAC device. If two HVAC devices have the same unique ID, Home Assistant will raise an exception.
   required: false
   type: string
value_template:
  description: Default template to render the payloads on *all* `*_state_topic`s with.
  type: template
  required: false
{% endconfiguration %}

## Optimistic mode

If a property works in *optimistic mode* (when the corresponding state topic is not set), Home Assistant will assume that any state changes published to the command topics did work and change the internal state of the entity immediately after publishing to the command topic. If it does not work in optimistic mode, the internal state of the entity is only updated when the requested update is confirmed by the device through the state topic. You can enforce optimistic mode by setting the `optimistic` option to `true`. When set, the internal state will always be updated, even when a state topic is defined.

## Using Templates

For all `*_state_topic`s, a template can be specified that will be used to render the incoming payloads on these topics. Also, a default template that applies to all state topics can be specified as `value_template`. This can be useful if you received payloads are e.g., in JSON format. Since in JSON, a quoted string (e.g., `"foo"`) is just a string, this can also be used for unquoting.

Say you receive the operation mode `"auto"` via your `mode_state_topic`, but the mode is actually called just `auto`, here's what you could do:

{% raw %}

```yaml
mqtt:
  climate:
    - name: Study
      modes:
        - "off"
        - "heat"
        - "auto"
      mode_command_topic: "study/ac/mode/set"
      mode_state_topic: "study/ac/mode/state"
      mode_state_template: "{{ value_json }}"
```

{% endraw %}

This will parse the incoming `"auto"` as JSON, resulting in `auto`. Obviously, in this case you could also just set `value_template: {% raw %}"{{ value_json }}"{% endraw %}`.

Similarly for `*_command_topic`s, a template can be specified to render the outgoing payloads on these topics.

## Example

A full configuration example looks like the one below.

{% raw %}

```yaml
# Full example configuration.yaml entry
mqtt:
  climate:
    - name: Study
      modes:
        - "off"
        - "cool"
        - "fan_only"
      swing_modes:
        - "on"
        - "off"
      fan_modes:
        - "high"
        - "medium"
        - "low"
      preset_modes:
        - "eco"
        - "sleep"
        - "activity"
      preset_mode_command_topic: "study/ac/preset_mode/set"
      mode_command_topic: "study/ac/mode/set"
      mode_command_template: "{{ value if value=="off" else "on" }}"
      temperature_command_topic: "study/ac/temperature/set"
      fan_mode_command_topic: "study/ac/fan/set"
      swing_mode_command_topic: "study/ac/swing/set"
      precision: 1.0
```

{% endraw %}