Better Thermostat - Intelligent Heating Control

Medium 30 min

Better Thermostat is a HACS integration that makes your “dumb” radiator thermostats smart. It uses an external temperature sensor, window sensors and weather data to optimize heating and save energy.

Open Source

Better Thermostat is open source! See Better Thermostat on GitHub for documentation and feature requests.

🤔 Why Better Thermostat?

Radiator thermostats (TRVs) measure the temperature right at the radiator - typically 2-5°C warmer than the rest of the room. Better Thermostat solves this:

Problem	Better Thermostat solution
Wrong temperature	Uses an external sensor for the real room temperature
Open window = waste	Stops heating automatically when a window opens
Manual adjustment	Presets: Eco, Comfort, Away, Boost
Multiple radiators	Group TRVs in the same room
Calibration	Automatic offset calibration

Energy savings

With an external sensor and window detection you can typically save 15-25% on your heating bill!

📦 What You Need

Hardware (you probably already own some of it)

Component	Examples	Required?
Radiator thermostat (TRV)	Shelly TRV, TRÅDFRI, Sonoff TRVZB, Aqara	✅ Yes
Temperature sensor	Shelly Wall Display, Aqara, IKEA Vindstyrka	✅ Recommended
Window sensor	Aqara, Sonoff, Shelly	⭐ Optional
Home Assistant	With HACS installed	✅ Yes

A typical starting point

The guide assumes a setup many people already have:

• Shelly TRV radiator thermostats in the living room
• Shelly Wall Display or another device with a temperature sensor
• Several temperature sensors around the house

🔧 Installation

Step 1: Install via HACS

1. Open HACS in Home Assistant
2. Click Integrations
3. Search for Better Thermostat
4. Click Download and restart Home Assistant

Step 2: Add Better Thermostat

1. Go to Settings → Devices & services
2. Click Add integration
3. Search for Better Thermostat
4. Follow the setup wizard

⚙️ Configuration

Basic setup

When creating the thermostat you specify:

Field	Description	Example
Name	Name of the thermostat	”Living Room Better”
Thermostat	Your existing TRV	climate.shelly_trv_living_room
Temperature Sensor	External room temperature sensor	sensor.shelly_wall_display_temperature
Window Sensor	Window sensor (optional)	binary_sensor.window_living_room

Advanced settings

After creation you can adjust these under Settings → Devices & services → Better Thermostat → Configure:

Setting	Internal key	Function
Outdoor Sensor	outdoor_sensor	Outdoor temperature, e.g. sensor.openweathermap_temperature
Off Temperature	off_temperature	Outdoor temperature at which heating switches off entirely
Window Delay	window_off_delay	Seconds before reacting to an open window (e.g. 30)
Window Delay After	window_off_delay_after	Seconds before heating resumes after the window closes
Tolerance	tolerance	Allowed deviation before the thermostat regulates
Presets	presets	Choose which presets (eco, comfort, away, etc.) are active

📊 Example: Living Room with 2 Radiators

Here is a complete example with a living room that has 2 Shelly TRVs:

Step 1: Create a Better Thermostat for the room

1. Add integration → Better Thermostat
2. Name: “Living Room Heating”
3. Thermostat: Select both TRVs (grouping)
   • climate.shelly_trv_living_room_1
   • climate.shelly_trv_living_room_2
4. Temperature Sensor: sensor.shelly_wall_display_temperature
5. Window Sensor: binary_sensor.window_living_room (if you have one)

Step 2: Verify entities

After creation you get:

# New climate entity
climate.living_room_heating:
  current_temperature: 21.5°C  # From the Wall Display
  target_temperature: 21°C
  preset_mode: comfort

# Attributes
hvac_action: heating
window_open: false

🎯 Presets and Schedules

Standard presets

Preset	Default temp	Use case
None	20°C	Default
Eco	19°C	Energy saving
Comfort	21°C	At home and active
Boost	24°C	Quick heat-up
Away	16°C	Not home
Sleep	18°C	Night

Adjust preset temperatures

# Via automation or service call
service: climate.set_temperature
target:
  entity_id: climate.living_room_heating
data:
  temperature: 22

🤖 Automations

Switch preset based on presence

automation:
  - alias: "Heating: Away when nobody home"
    trigger:
      - platform: state
        entity_id: group.people_home
        to: "not_home"
        for:
          minutes: 30
    action:
      - service: climate.set_preset_mode
        target:
          entity_id:
            - climate.living_room_heating
            - climate.bedroom_heating
            - climate.office_heating
        data:
          preset_mode: away

  - alias: "Heating: Comfort when home"
    trigger:
      - platform: state
        entity_id: group.people_home
        to: "home"
    action:
      - service: climate.set_preset_mode
        target:
          entity_id:
            - climate.living_room_heating
            - climate.bedroom_heating
        data:
          preset_mode: comfort

Night mode

automation:
  - alias: "Heating: Sleep at night"
    trigger:
      - platform: time
        at: "22:30:00"
    action:
      - service: climate.set_preset_mode
        target:
          entity_id:
            - climate.living_room_heating
            - climate.bedroom_heating
        data:
          preset_mode: sleep

  - alias: "Heating: Comfort in the morning"
    trigger:
      - platform: time
        at: "06:30:00"
    condition:
      - condition: state
        entity_id: group.people_home
        state: "home"
    action:
      - service: climate.set_preset_mode
        target:
          entity_id:
            - climate.living_room_heating
            - climate.bedroom_heating
        data:
          preset_mode: comfort

Boost on office presence

automation:
  - alias: "Office: Boost on presence"
    trigger:
      - platform: state
        entity_id: binary_sensor.office_presence
        to: "on"
    condition:
      - condition: numeric_state
        entity_id: sensor.office_temperature
        below: 20
    action:
      - service: climate.set_preset_mode
        target:
          entity_id: climate.office_heating
        data:
          preset_mode: boost
      # Switch to comfort after 30 min
      - delay:
          minutes: 30
      - service: climate.set_preset_mode
        target:
          entity_id: climate.office_heating
        data:
          preset_mode: comfort

🪟 Window Detection

Better Thermostat can automatically stop heating when a window opens:

With a physical sensor

# Configured at creation or via Options
window_sensors: binary_sensor.window_living_room
window_off_delay: 30        # Wait 30 sec before stopping the heat
window_off_delay_after: 0   # Resume heating immediately when the window closes

Without a sensor (temperature-based)

Better Thermostat has no built-in temperature-drop detection. If you lack a physical sensor, you can instead create a virtual window sensor that switches to “on” after a sudden temperature drop:

1. Install the community blueprint Window open detection by temperature
2. Create an automation from the blueprint using your room temperature sensor and an input_boolean as the “window”
3. Select the input_boolean/binary_sensor as Window Sensor in Better Thermostat

📱 Dashboard Card

Better Thermostat UI Card

Install the matching UI card to see extra info:

1. Open HACS → Frontend
2. Search for Better Thermostat UI Card
3. Install and reload your browser

# Lovelace card configuration
type: custom:better-thermostat-ui-card
entity: climate.living_room_heating
eco_temperature: 19
disable_window: false
disable_summer: false

Standard Thermostat Card

type: thermostat
entity: climate.living_room_heating
features:
  - type: climate-preset-modes
    preset_modes:
      - eco
      - comfort
      - boost
      - away
      - sleep

🔧 Calibration

Better Thermostat automatically calibrates your TRV based on the difference between the TRV’s built-in sensor and your external sensor.

How it works

1. The TRV measures 24°C (at the radiator)
2. The external sensor measures 21°C (in the room)
3. Better Thermostat calculates the offset: -3°C
4. Sends the calibration to the TRV

📊 Energy Monitoring

Combine with the Energy dashboard:

# Add to configuration.yaml
template:
  - sensor:
      - name: "Living Room Heating Status"
        state: >
          {% if is_state_attr('climate.living_room_heating', 'hvac_action', 'heating') %}
            Heating
          {% else %}
            Idle
          {% endif %}

# history_stats measures how long the status sensor has been "Heating" today
sensor:
  - platform: history_stats
    name: "Daily Heating Time Living Room"
    entity_id: sensor.living_room_heating_status
    state: "Heating"
    type: time   # Result in hours
    start: "{{ today_at() }}"
    end: "{{ now() }}"

🔧 Troubleshooting

TRV not responding?

1. Check that the TRV is online in Home Assistant
2. Verify that Better Thermostat uses the correct entity
3. Check that the TRV supports temperature calibration
4. Restart the Better Thermostat integration

Temperature jumping?

• Reduce the update frequency of the external sensor
• Enable “smooth temperature” in Options
• Check that the sensor isn’t affected by sun/draft

Window detection not working?

• Increase window_off_delay to 60 seconds
• Verify that the sensor entity is correct
• Check that the sensor reports “on” when the window is open

🚀 Advanced: Multiple Rooms

Recommended structure

climate.living_room_heating → Shelly TRV x2 + Wall Display temp
climate.bedroom_heating     → Shelly TRV + Aqara temp sensor
climate.office_heating      → Shelly TRV + LD2410 temp (ESP32)
climate.bathroom_heating    → Shelly TRV + Wall Display temp

Group all Better Thermostats

# groups.yaml
heating_all_rooms:
  name: "All rooms heating"
  entities:
    - climate.living_room_heating
    - climate.bedroom_heating
    - climate.office_heating
    - climate.bathroom_heating

📈 Next Steps

🌡️ Shelly Wall Display

Perfect temperature sensor for Better Thermostat.

Set up Wall Display →

📊 LD2410 mmWave

Combine presence with heating control.

Build a presence sensor →