Home Assistant Dual Smart Thermostat component

The dual_smart_thermostat is an enhanced version of generic thermostat implemented in Home Assistant.

Features

Feature	Icon	Documentation
Heater/Cooler Mode (Heat-Cool)		docs
Heater Only Mode		docs
Cooler Only Mode		docs
Two Stage (AUX) Heating Mode		docs
Fan Only Mode		docs
Fan With Cooler Mode		docs
Fan Speed Control		docs
Dry Mode (Humidity Control)		docs
Heat Pump Mode		docs
Floor Temperature Control		docs
Window/Door Sensor Integration (Openings)		docs
Preset Modes Support		docs
HVAC Action Reason Tracking		docs

Examples

Looking for ready-to-use configurations? Check out our examples directory with:

Basic Configurations - Simple setups for heater-only, cooler-only, heat pumps, and dual-mode systems
Advanced Features - Floor heating limits, two-stage heating, opening detection, and presets
Integration Patterns - Smart scheduling and automation examples
Single-Mode Thermostat Wrapper - Create Nest-like "Keep Between" functionality on single-mode thermostats

Each example includes complete YAML configurations with detailed explanations, troubleshooting tips, and best practices.

Heat/Cool Mode

If both heater and cooler entities configured. The thermostat can control heating and cooling and you are able to set min/max low and min/max high temperatures. In this mode you can turn the thermostat to heat only, cooler only and back to heat/cool mode.

Heat/Cool With Fan Mode

If the fan entity is set the thermostat can control the fan mode of the AC. The fan will turn on when the temperature is above the target temperature and the fan_hot_tolerance is not reached. If the temperature is above the target temperature and the fan_hot_tolerance is reached the AC will turn on.

all features ⤴️

Heater Only Mode

If only the heater entity is set the thermostat works only in heater mode.

all features ⤴️

Two Stage (AUX) Heating

Two stage or AUX heating can be enabled by adding the required configuration entities: secondary_heater, secondary heater_timeout. If these are set the feature will enable automatically. Optionally you can set secondary heater_dual_mode to true to turn on the secondary heater together with the primary heater.

How Two Stage Heating Works?

If the timeout ends and the heater was on for the whole time, the thermostat switches to the secondary heater. In this case, the primary heater (heater) will be turned off. This will be remembered for the day it turned on, and in the next heating cycle, the secondary heater will turn on automatically. On the following day the primary heater will turn on again, and the second stage will again only turn on after a timeout. If the third secondary heater_dual_mode is set to true, the secondary heater will be turned on together with the primary heater.

Two Stage Heating Example

secondary_heater: switch.study_secondary_heater   # <-- required
secondary_heater_timeout: 00:00:30                 # <-- required
secondary_heater_timeout: true                   # <-- optional

Fan Only Mode

If the fan_mode entity is set to true the thermostat works only in fan mode. The heater entity will be treated as a fan only device.

Fan Only Mode Example

heater: switch.study_heater
fan_mode: true

Fan With Cooler Mode

If the ac_mode is set to true and the fan entity is also set, the heater entity will be treated as a cooler (AC) device with an additional fan device. This will allow not only the use of a separate physical fan device but also turning on the fan mode of an AC using advanced switches. With this setup, you can use your AC's fan mode more easily.

Fan With Cooler Mode Example

heater: switch.study_heater
ac_mode: true
fan: switch.study_fan

Fan Hot Tolerance

If you also set the fan_hot_tolerance the fan will turn on when the temperature is above the target temperature and the fan_hot_tolerance is not reached. If the temperature is above the target temperature and the fan_hot_tolerance is reached the AC will turn on.

Cooler With Auto Fan Mode Example

heater: switch.study_heater
ac_mode: true
fan: switch.study_fan
fan_hot_tolerance: 0.5

Outside Temperature And Fan Hot Tolerance

If you set the fan_hot_tolerance, outside_sensor and the fan_air_outside the fan will turn on only if the outside temperature is colder than the inside temperature and the fan_hot_tolerance is not reached. If the outside temperature is colder than the inside temperature and the fan_hot_tolerance is reached the AC will turn on.

Fan Speed Control

The dual_smart_thermostat automatically detects and enables fan speed control when you configure a fan entity that supports speed capabilities. This allows you to control your HVAC fan speeds (low, medium, high, auto) directly from the thermostat interface, just like built-in thermostats.

Automatic Detection

The thermostat automatically detects whether your fan entity supports speed control based on its capabilities:

Native fan entities (fan domain) with preset_mode or percentage attributes → Fan speed control enabled automatically
Switch entities (switch domain) → Traditional on/off control (backward compatible)

No configuration changes required - the thermostat detects capabilities at runtime.

Fan Speed Control Example

climate:
  - platform: dual_smart_thermostat
    name: My Thermostat
    heater: switch.study_heater
    fan: fan.hvac_fan  # Native fan entity - speeds automatically detected
    target_sensor: sensor.study_temperature

With this configuration, you'll see fan speed controls in the thermostat UI allowing you to select speeds like "auto", "low", "medium", "high" depending on what your fan entity supports.

Backward Compatibility

Existing configurations using switch entities continue working unchanged:

climate:
  - platform: dual_smart_thermostat
    name: My Thermostat
    heater: switch.study_heater
    fan: switch.fan_relay  # Switch entity - on/off only (no speed control)
    target_sensor: sensor.study_temperature

Integration with Existing Features

Fan speed control works seamlessly with all existing fan-related features:

FAN_ONLY Mode: Fan runs at selected speed in fan-only mode
Fan with AC (fan_on_with_ac): Fan runs at selected speed when AC is active
Fan Hot Tolerance: Fan activates at selected speed when temperature tolerance is exceeded
Heat Pump Mode: Fan speed applies to both heating and cooling operations

Your fan speed selection persists across heating/cooling cycles and restarts.

Upgrading Switch-Based Fans

If you currently use a switch entity for your fan but want speed control, you can create a template fan entity that wraps your switch. Here are several examples:

Template Fan with Input Select (Preset Modes)

This example uses an input_select helper to provide speed presets:

# Helper for fan speed selection
input_select:
  hvac_fan_speed:
    name: HVAC Fan Speed
    options:
      - "auto"
      - "low"
      - "medium"
      - "high"
    initial: "auto"

# Template fan wrapping switch + speed control
fan:
  - platform: template
    fans:
      hvac_fan:
        friendly_name: "HVAC Fan"
        value_template: "{{ is_state('switch.fan_relay', 'on') }}"
        preset_mode_template: "{{ states('input_select.hvac_fan_speed') }}"
        preset_modes:
          - "auto"
          - "low"
          - "medium"
          - "high"
        turn_on:
          service: switch.turn_on
          target:
            entity_id: switch.fan_relay
        turn_off:
          service: switch.turn_off
          target:
            entity_id: switch.fan_relay
        set_preset_mode:
          service: input_select.select_option
          target:
            entity_id: input_select.hvac_fan_speed
          data:
            option: "{{ preset_mode }}"

# Use in thermostat
climate:
  - platform: dual_smart_thermostat
    name: My Thermostat
    heater: switch.study_heater
    fan: fan.hvac_fan  # Uses template fan with speed control
    target_sensor: sensor.study_temperature

Template Fan with Percentage Control

This example uses an input_number helper for percentage-based speed control:

# Helper for fan percentage
input_number:
  hvac_fan_speed:
    name: HVAC Fan Speed
    min: 0
    max: 100
    step: 1
    unit_of_measurement: "%"

# Template fan with percentage support
fan:
  - platform: template
    fans:
      hvac_fan:
        friendly_name: "HVAC Fan"
        value_template: "{{ is_state('switch.fan_relay', 'on') }}"
        percentage_template: "{{ states('input_number.hvac_fan_speed') | int }}"
        turn_on:
          service: switch.turn_on
          target:
            entity_id: switch.fan_relay
        turn_off:
          service: switch.turn_off
          target:
            entity_id: switch.fan_relay
        set_percentage:
          - service: input_number.set_value
            target:
              entity_id: input_number.hvac_fan_speed
            data:
              value: "{{ percentage }}"

# Use in thermostat
climate:
  - platform: dual_smart_thermostat
    name: My Thermostat
    heater: switch.study_heater
    fan: fan.hvac_fan  # Percentage-based speed control
    target_sensor: sensor.study_temperature

Template Fan for IR/RF Controlled Fans

For fans controlled via Broadlink, IR blaster, or RF remote:

# Helpers to track state
input_boolean:
  fan_state:
    name: Fan State

input_select:
  hvac_fan_speed:
    name: HVAC Fan Speed
    options:
      - "low"
      - "medium"
      - "high"
    initial: "low"

# Template fan for IR/RF control
fan:
  - platform: template
    fans:
      hvac_fan:
        friendly_name: "HVAC Fan"
        value_template: "{{ is_state('input_boolean.fan_state', 'on') }}"
        preset_mode_template: "{{ states('input_select.hvac_fan_speed') }}"
        preset_modes:
          - "low"
          - "medium"
          - "high"
        turn_on:
          - service: input_boolean.turn_on
            target:
              entity_id: input_boolean.fan_state
          - service: remote.send_command
            target:
              entity_id: remote.living_room
            data:
              command: "fan_on"
        turn_off:
          - service: input_boolean.turn_off
            target:
              entity_id: input_boolean.fan_state
          - service: remote.send_command
            target:
              entity_id: remote.living_room
            data:
              command: "fan_off"
        set_preset_mode:
          - service: input_select.select_option
            target:
              entity_id: input_select.hvac_fan_speed
            data:
              option: "{{ preset_mode }}"
          - service: remote.send_command
            target:
              entity_id: remote.living_room
            data:
              command: "fan_{{ preset_mode }}"

# Use in thermostat
climate:
  - platform: dual_smart_thermostat
    name: My Thermostat
    heater: switch.study_heater
    fan: fan.hvac_fan  # IR/RF controlled with speed support
    target_sensor: sensor.study_temperature

Benefits of Template Fans:

Use existing switch hardware without buying new devices
Add speed control functionality to any fan
Automatic detection by the thermostat
Full UI integration with speed controls
Works with IR/RF remotes, relays, or any controllable device

Reference: Home Assistant Template Fan Documentation

all features ⤴️

AC With Fan Switch Support

Some AC systems have independent fan controls to cycle the house air for filtering or humidity control, without using the heating or cooling elements. Central AC systems require the thermostat to turn on both the AC wire ("Y" wire) and the air-handler/fan wire ("G" wire) to activate the AC

This feature lets you do just that.

To use this feature, you need to set the heater entity, the ac_mode, and the fan) entity and the fan_on_with_ac to true.

example

heater: switch.study_heater
ac_mode: true
fan: switch.study_fan
fan_on_with_ac: true

Cooler Only Mode

If only the cooler entity is set, the thermostat works only in cooling mode.

all features ⤴️

Dry mode

If the dryer entity is set, the thermostat can switch to dry mode. The dryer will turn on when the humidity is above the target humidity and the moist_tolerance is not reached. If the humidity is above the target humidity and the moist_tolerance is reached, the dryer will stop.

Dry Mode Example with cooler

heater: switch.study_heater
target_sensor: sensor.study_temperature
ac_mode: true
dryer: switch.study_dryer
humidity_sensor: sensor.study_humidity
moist_tolerance: 5
dry_tolerance: 5

Dryer example in dual mode

heater: switch.study_heater
cooler: switch.study_cooler
target_sensor: sensor.study_temperature
dryer: switch.study_dryer
humidity_sensor: sensor.study_humidity
moist_tolerance: 5
dry_tolerance: 5

Heat Pump (one switch heat/cool) mode

This setup allows you to use a single switch for both heating and cooling. To enable this mode, you define only a single switch for the heater and set your heat pump's current state (heating or cooling) as for the heat_pump_cooling attribute. This must be an entity ID of a sensor with a state of on or off.

The entity can be a Boolean input for manual control or an entity provided by the heat pump.

heater: switch.study_heat_pump
target_sensor: sensor.study_temperature
heat_pump_cooling: sensor.study_heat_pump_state

Heat Pump HVAC Modes

Heat-Cool Mode

heater: switch.study_heat_pump
target_sensor: sensor.study_temperature
heat_pump_cooling: sensor.study_heat_pump_state
heat_cool_mode: true

heating (heat_pump_cooling: false):

heat/cool
heat
off

cooling (heat_pump_cooling: true):

heat/cool
cool
off

Single mode

heater: switch.study_heat_pump
target_sensor: sensor.study_temperature
heat_pump_cooling: sensor.study_heat_pump_state
heat_cool_mode: false # <-- or not set

heating (heat_pump_cooling: false):

heat
off

cooling (heat_pump_cooling: true):

cool
off

Openings

The dual_smart_thermostat can turn off heating or cooling when a window or door is opened and turn it back on when the door or window is closed, saving energy. The openings configuration variable accepts a list of opening entities and opening objects.

Opening entities and objects

An opening entity is a sensor that can be in two states: on or off. If the state is on, the opening is considered open; if the state is off, the opening is considered closed. The opening object can contain a timeout and a closing_timeout property that defines the time for which the opening is still considered closed or open, even if the state is on or off. This is useful if you want to ignore windows that are only open or closed for a short time.

Openings Scope

The openings_scope configuration variable defines the scope of the openings. If set to all or not defined, any open openings will turn off the current HVAC device, and it will be in the idle state. If set, only devices that are operating in the defined HVAC modes will be turned off. For example, if set to heat, only the heater will be turned off if any of the openings are open.

Openings Scope Configuration

openings_scope: [heat, cool, heat_cool, fan_only, dry]

openings_scope:
  - heat
  - cool

Openings Configuration

# Example configuration.yaml entry
climate:
  - platform: dual_smart_thermostat
    name: Study
    heater: switch.study_heater
    cooler: switch.study_cooler
    openings:
      - binary_sensor.window1
      - entity_id: binary_sensor.window2
        timeout: 00:00:30
      - entity_id: binary_sensor.window3
        timeout: 00:00:30
        closing_timeout: 00:00:15
    openings_scope: [heat, cool]
    target_sensor: sensor.study_temperature

all features ⤴️

Floor heating temperature control

The dual_smart_thermostat can control the floor heating temperature. The thermostat can turn off if the floor heating reaches the maximum allowed temperature you define in order to protect the floor from overheating and damage. These limits also can be set in presets.

Maximum floor temperature

The dual_smart_thermostat can turn off if the floor heating reaches the maximum allowed temperature you define in order to protect the floor from overheating and damage. There is a default value of 28 degrees Celsius as per inustry recommendations. To enable this protection you need to set two variables:

floor_sensor: sensor.floor_temp
max_floor_temp: 28

Set in presets

You can also set the max_floor_temp in the presets configuration. This will allow you to set different maximum floor temperatures for different presets.

floor_sensor: sensor.floor_temp
max_floor_temp: 28
preset_name:
  max_floor_temp: 25

Minimum floor temperature

The dual_smart_thermostat can turn on if the floor temperature reaches the minimum required temperature you define in order to protect the floor from freezing or to keep it on a comfortable temperature.

floor_sensor: sensor.floor_temp
min_floor_temp: 5

Set in presets

You can also set the min_floor_temp in the presets configuration. This will allow you to set different minimum floor temperatures for different presets.

floor_sensor: sensor.floor_temp
min_floor_temp: 5
preset_name:
  min_floor_temp: 8

Floor Temperature Control Configuration

# Example configuration.yaml entry
climate:
  - platform: dual_smart_thermostat
    name: Study
    unique_id: study
    heater: switch.study_heater
    cooler: switch.study_cooler
    target_sensor: sensor.study_temperature
    floor_sensor: sensor.floor_temp
    max_floor_temp: 28
    min_floor_temp: 5

all features ⤴️

Presets

Currently supported presets are:

none
home
away
eco
sleep
comfort
anti freeze
activity
boost

To set presets you need to add entries for them in the configuration file like this:

You have 6 options here:

Set the temperature for heat, cool or fan-only mode
Set the target_temp_low and target_temp_high for heat_cool mode. If temperature is not set but target_temp_low and target_temp_high are set, the temperature will be picked based on hvac mode. For heat mode it will be target_temp_low and for cool, fan_only mode it will be target_temp_high
Set the humidity for dry mode
Set min_floor_temp for floor heating temperature control
Set max_floor_temp for floor heating temperature control
Set all above

Presets Configuration

preset_name:
  temperature: 13
  humidity: 50 # <-- only if dry mode configured
  target_temp_low: 12
  target_temp_high: 14
  min_floor_temp: 5
  max_floor_temp: 28

HVAC Action Reason

State attribute: hvac_action_reason

The dual_smart_thermostat will set the hvac_action attribute to heating, cooling, idle or off based on the current state of the thermostat. The hvac_action attribute is used to indicate the current action of the thermostat. The dual_smart_thermostat will also set the hvac_action_reason attribute based on the current state of the thermostat. The hvac_action_reason attribute is used to indicate the reason for the current action of the thermostat.

HVAC Action Reason values

The hvac_action_reason attribute is grouped by internal and external values. The internal values can be set by the component only and the external values can be set by the user or automations.

HVAC Action Reason Internal values

Value	Description
`none`	No action reason
`target_temp_not_reached`	The target temperature has not been reached
`target_temp_not_reached_with_fan`	The target temperature has not been reached trying it with a fan
`target_temp_reached`	The target temperature has been reached
`target_humidity_reached`	The target humidity has been reached
`target_humidity_not_reached`	The target humidity has not been reached
`misconfiguration`	The thermostat is misconfigured
`opening`	The thermostat is idle because an opening is open
`limit`	The thermostat is idle because the floor temperature is at the limit
`overheat`	The thermostat is idle because the floor temperature is too high
`temperature_sensor_stalled`	The thermostat is idle because the temperature sensor is not provided data for the defined time that could indicate a malfunctioning sensor
`humidity_sensor_sstalled`	The thermostat is idle because the temperature sensor is not provided data for the defined time that could indicate a malfunctioning sensor

HVAC Action Reason External values

Value	Description
`none`	No action reason
`presence`	the last HVAc action was triggered by presence
`schedule`	the last HVAc action was triggered by schedule
`emergency`	the last HVAc action was triggered by emergency
`malfunction`	the last HVAc action was triggered by malfunction

all features ⤴️

Services

Set HVAC Action Reason

dial_smart_thermostat.set_hvac_action_reason is exposed for automations to set the hvac_action_reason attribute. The service accepts the following parameters:

Parameter	Description	Type	Required
entity_id	The entity id of the thermostat	string	yes
hvac_action_reason	The reason for the current action of the thermostat	HVACActionReasonExternal	yes

Configuration variables

name

(required) (string) Name of thermostat

default: Dual Smart

unique_id

(optional) (string) the unique id for the thermostat. It allows you to customize it in the UI and to assign the component to an area.

_default: none

heater

(required) (string) "entity_id for heater switch, must be a toggle device. Becomes air conditioning switch when ac_mode is set to true"

secondary_heater

(optional, required for two stage heating) (string) "entity_id for secondary heater switch, must be a toggle device.

secondary_heater_timeout

(optional, required for two stage heating) (time, integer) Set a minimum amount of time that the switch specified in the heater option must be in its ON state before secondary heater devices needs to be turned on.

secondary_heater_dual_mode

(optional, (bool) If set true the secondary (aux) heater will be turned on together with the primary heater.

cooler

(optional) (string) "entity_id for cooler switch, must be a toggle device."

fan_mode

(optional) (bool) If set to true the heater entity will be treated as a fan only device.

fan

(optional) (string) "entity_id for fan switch, must be a toggle device."

fan_hot_tolerance

(optional) (float) Temperature range above hot_tolerance where the fan is used instead of the AC. This creates an intermediate zone where the fan attempts to cool before engaging the AC.

Example: With target temperature 25°C, hot_tolerance 1°C, and fan_hot_tolerance 0.5°C:

At 26°C (target + hot_tolerance): Fan turns on
At 26.5°C (target + hot_tolerance + fan_hot_tolerance): AC turns on (fan turns off)

This feature helps save energy by using the fan for minor temperature increases before engaging the more power-intensive AC.

default: 0.5

requires: fan

fan_hot_tolerance_toggle

(optional) (string) entity_id for an input_boolean or binary_sensor that dynamically enables/disables the fan_hot_tolerance feature.

When the toggle entity is on (or not configured): The fan_hot_tolerance feature is active
When the toggle entity is off: The AC is used immediately when hot_tolerance is exceeded (bypasses fan zone)

Useful for automations that disable fan-first behavior during extreme heat, high humidity, or other conditions where immediate AC is preferred.

default: Feature enabled (behaves as if toggle is on)

requires: fan

fan_on_with_ac

(optional) (boolean) If set to true the fan will be turned on together with the AC. This is useful for central AC systems that require the fan to be turned on together with the AC.

requires: fan

fan_air_outside

(optional) (boolean) "If set to true the fan will be turned on only if the outside temperature is colder than the inside temperature and the fan_hot_tolerance is not reached. If the outside temperature is colder than the inside temperature and the fan_hot_tolerance is reached the AC will turn on."

requires: fan , sensor_outside

dryer

(optional) (string) "entity_id for dryer switch, must be a toggle device."

moist_tolerance

(optional) (float) Set a minimum amount of difference between the humidity read by the sensor specified in the humidity_sensor option and the target humidity that must change prior to being switched on. For example, if the target humidity is 50 and the tolerance is 5 the dryer will start when the sensor equals or goes below 45.

requires: dryer, humidity_sensor

dry_tolerance

(optional) (float) Set a minimum amount of difference between the humidity read by the sensor specified in the humidity_sensor option and the target humidity that must change prior to being switched off. For example, if the target humidity is 50 and the tolerance is 5 the dryer will stop when the sensor equals or goes above 55.

requires: dryer, humidity_sensor

humidity_sensor

(optional) (string) "entity_id for a humidity sensor, humidity_sensor.state must be humidity."

target_sensor

(required) (string) "entity_id for a temperature sensor, target_sensor.state must be temperature."

sensor_stale_duration

(optional) (timedelta) Set a delay for the target sensor to be considered not stalled. If the sensor is not available for the specified time or doesn't get updated the thermostat will be turned off.

requires: target_sensor and/or huidity_sensor

floor_sensor

(optional) (string) "entity_id for the floor temperature sensor, floor_sensor.state must be temperature."

outside_sensor

(optional) (string) "entity_id for the outside temperature sensor, oustide_sensor.state must be temperature."

openings

(optional) (list) "list of opening entity_id's and/or objects for detecting open windows or doors that will idle the thermostat until any of them are open. Note: if min_floor_temp is set and the floor temperature is below the minimum temperature, the thermostat will not idle even if any of the openings are open."

entity_id: <value> The entity id of the opening bstate sensor (string)

timeout: <value> The time for which the opening is still considered closed even if the state of the sensor is on (timedelta)

closing_timeout: <value> The time for which the opening is still considered open even if the state of the sensor is off (timedelta)

openings_scope

(optional) (array[string]) "The scope of the openings. If set to [all] or not defined, any open openings will turn off the current hvac device and it will be in the idle state. If set, only devices that operating in the defined HVAC modes will be turned off. For example, if set to heat only the heater will be turned off if any of the openings are open."

default: all

options: - all - heat - cool - heat_cool - fan_only

heat_pump_cooling

(optional) (string) "entity_id for the heat pump cooling state sensor, heat_pump_cooling.state must be on or off." enables heat pump mode

min_temp

(optional) (float)

default: 7

max_temp

(optional) (float)

default: 35

max_floor_temp

(optional) (float)

default: 28

min_floor_temp

(optional) (float)

target_temp

(optional) (float) Set initial target temperature. If this variable is not set, it will retain the target temperature set before restart if available.

target_temp_low

(optional) (float) Set initial target low temperature. If this variable is not set, it will retain the target low temperature set before restart if available.

target_temp_high

(optional) (float) Set initial target high temperature. If this variable is not set, it will retain the target high temperature set before restart if available.

ac_mode

(optional) (boolean) Set the switch specified in the heater option to be treated as a cooling device instead of a heating device. This parameter will be ignored if cooler entity is defined.

default: false

heat_cool_mode

(optional) (boolean) If variable target_temp_low and target_temp_high are not set, this parameter must be set to true to enable the heat_cool mode.

default: false

min_cycle_duration

(optional) (time, integer) Set a minimum amount of time that the switch specified in the heater and/or cooler option must be in its current state prior to being switched either off or on. This option will be ignored if the keep_alive option is set.

cold_tolerance

(optional) (float) Set a minimum amount of difference between the temperature read by the sensor specified in the target_sensor option and the target temperature that must change prior to being switched on. For example, if the target temperature is 25 and the tolerance is 0.5 the heater will start when the sensor equals or goes below 24.5.

default: 0.3

hot_tolerance

(optional) (float) Set a minimum amount of difference between the temperature read by the sensor specified in the target_sensor option and the target temperature that must change prior to being switched off. For example, if the target temperature is 25 and the tolerance is 0.5 the heater will stop when the sensor equals or goes above 25.5.

default: 0.3

heat_tolerance

(optional) (float) [Dual-mode systems only] Set a mode-specific tolerance for heating operations. Only available for systems that support both heating and cooling (heater_cooler or heat_pump system types).

When configured, this tolerance is used instead of cold_tolerance when the system is actively heating. This allows you to have different tolerance values for heating vs cooling operations.

Example use case: Tight temperature control during heating (±0.3°C) while allowing looser control during cooling (±2.0°C) for energy savings.

Priority: If set, heat_tolerance takes priority over cold_tolerance for heating operations.

Availability:

✅ Available: heater_cooler, heat_pump (dual-mode systems)
❌ Not available: simple_heater, ac_only (single-mode systems use legacy tolerances)

default: Uses cold_tolerance if not set

cool_tolerance

(optional) (float) [Dual-mode systems only] Set a mode-specific tolerance for cooling operations. Only available for systems that support both heating and cooling (heater_cooler or heat_pump system types).

When configured, this tolerance is used instead of hot_tolerance when the system is actively cooling. This allows you to have different tolerance values for heating vs cooling operations.

Example use case: Allow wider temperature swings during cooling to reduce energy consumption while maintaining comfort.

Priority: If set, cool_tolerance takes priority over hot_tolerance for cooling operations.

Availability:

✅ Available: heater_cooler, heat_pump (dual-mode systems)
❌ Not available: simple_heater, ac_only (single-mode systems use legacy tolerances)

default: Uses hot_tolerance if not set

keep_alive

(optional) (time, integer) Set a keep-alive interval. If set, the switch specified in the heater and/or cooler option will be triggered every time the interval elapses. Use with heaters and A/C units that shut off if they don't receive a signal from their remote for a while. Use also with switches that might lose state. The keep-alive call is done with the current valid climate integration state (either on or off). When keep_alive is set the min_cycle_duration option will be ignored.

default: 300 seconds (5 minutes)

Note: Some AC units (like certain Hitachi models) beep with each command they receive. If your AC beeps excessively every few minutes, the keep-alive feature may be sending redundant commands. You can disable keep-alive by setting it to 0:

keep_alive: 0  # Disables keep-alive to prevent beeping

initial_hvac_mode

(optional) (string) Set the initial HVAC mode. Valid values are off, heat, cool or heat_cool. Value has to be double quoted. If this parameter is not set, it is preferable to set a keep_alive value. This is helpful to align any discrepancies between dual_smart_thermostat heater and cooler state.

NOTE! If this is set, the saved state will not be restored after HA restarts.

away

(optional) (list) Set the temperatures used by preset_mode: away. If this is not specified, the preset mode feature will not be available.

Possible values are: