Eurotronic Comet Blue

The Eurotronic Comet Blue integrationIntegrations connect and integrate Home Assistant with your devices, services, and more. [Learn more] allows you to integrate Eurotronic Comet Blue (and similar) thermostats.

Use cases

You can use this integration to read thermostat status, adjust temperatures, and manage schedule-related settings in Home Assistant.

You can also combine your thermostats with other Home Assistant entities to automate heating around your routine. For example, you can:

• Adjust daily heating schedules based on calendar events or outdoor temperatures, such as starting heating earlier on colder days, and restore your regular schedule when those conditions no longer apply.
• Select the Comfort preset when a device tracker detects that you have returned home early, rather than waiting for the next scheduled heating period.
• Synchronize the thermostat’s clock after a daylight saving time change to keep heating schedules aligned with local time.
• Compare the thermostat’s temperature reading with a separate room sensor to help adjust the Setpoint offset, since the thermostat measures temperature at the radiator.

Supported devices

• Eurotronic Comet Blue
• Sygonix HT100 BT
• Xavax Hama
• Lidl Silvercrest RT2000BT

Prerequisites

Before you set up this integration, make sure the following requirements are met:

1. The Bluetooth integration is enabled and working.
2. Bluetooth active scanning is enabled.

The Eurotronic Comet Blue integrationIntegrations connect and integrate Home Assistant with your devices, services, and more. [Learn more] will automatically discover devices once the Bluetooth integration is enabled and functional.

Configuration

To add the Eurotronic Comet Blue device to your Home Assistant instance, use this My button:

Supported functionality

This integration provides climate control and thermostat configuration entities.

Comet Blue devices run on an internal schedule and can be manually controlled temporarily. When the schedule is active, the thermostat switches between low and high target temperatures based on that schedule.

If you manually change the target temperature or use presets, the thermostat returns to its programmed schedule on the next schedule change.

You can read and adjust the schedule from Home Assistant via the provided actionsAn action makes Home Assistant do something, for example, turn on a light, send a notification, or activate a scene. Automations and scripts run a list of actions. [Learn more].

Climate

The climate entity lets you control the thermostat by setting a target temperature which the device will try to reach on its own.

As shortcuts, the climate platform supports the following presets:

• Eco: Temperature is set to the low schedule temperature.
• Comfort: Temperature is set to the high schedule temperature.
• Boost: Valve is fully open.
• Away: Holiday mode is currently active. Display only.
• None: Temperature is other than the above. Display only.

Additionally, the following modes are available:

• Off: Valve is fully closed.
• Heat: Valve is fully open.
• Auto: The thermostat controls the temperature automatically, based on the target temperature.

Button

The integration provides a Sync time button for each device. Pressing this button synchronizes the thermostat’s internal clock with Home Assistant’s current time.

Number

Number entities provide specific settings that affect automatic thermostat behavior.

• Comfort setpoint: Temperature used for the Comfort preset and if schedule is on.
• Eco setpoint: Temperature used for the Eco preset and if schedule is off.
• Setpoint offset: Temperature calibration for the internal thermostat control.

Sensor

The device reports its current battery level, but the reading may not be very accurate.

List of actions

The Eurotronic Comet Blue integrationIntegrations connect and integrate Home Assistant with your devices, services, and more. [Learn more] provides the following actions. Each link below opens a dedicated page with examples, parameters, and a step-by-step UI walkthrough.

• Get schedule (eurotronic_cometblue.get_schedule) Retrieves the configured heating time ranges of one or multiple devices.

• Set holiday/away mode (eurotronic_cometblue.set_holiday) Set holiday/away mode on a thermostat.

• Set schedule (eurotronic_cometblue.set_schedule) Push a schedule to a thermostat.

For an overview of every action across all integrations, see the actions reference.

Automation examples

Use these examples as a starting point. Replace the entity IDs with the ones from your Home Assistant instance.

Sync the thermostat clock after a daylight saving time change

Home Assistant checks the daylight saving time status each day at 5:00 AM. When the status differs from the previous day, it presses the thermostat’s Sync time button.

• Trigger: Time
  • At time: 05:00
• Condition: Daylight saving time status changed since the previous day
• Action: Press button
  • Target: Living room sync time button

alias: "Sync thermostat clock after daylight saving time change"
triggers:
  - trigger: time
    at: "05:00:00"
conditions:
  - "{{ now().timetuple().tm_isdst != (now() - timedelta(days=1)).timetuple().tm_isdst}}"
actions:
  - action: button.press
    target:
      entity_id: button.living_room_sync_time

Select the Comfort preset when you return home early

When a device tracker changes to home, this automation selects the Comfort preset. If holiday mode is active, Home Assistant cannot change the preset. To turn off holiday mode, press and hold the thermostat’s MENU button until it resets.

• Trigger: State changed
  • Entity: Phone device tracker
  • To: Home
• Action: Set thermostat preset mode
  • Target: Living room radiator thermostat
  • Preset mode: comfort

alias: "Set thermostat to Comfort when I get home"
triggers:
  - trigger: state
    entity_id: device_tracker.phone
    to: "home"
actions:
  - action: climate.set_preset_mode
    target:
      entity_id: climate.living_room_radiator
    data:
      preset_mode: comfort

Data updates

The integration pollsData polling is the process of querying a device or service at regular intervals to check for updates or retrieve data. By defining a custom polling interval, you can control how frequently your system checks for new data, which can help optimize performance and reduce unnecessary network traffic. [Learn more] data from the thermostat every 5 minutes by default.

Known limitations

• The devices only support temperature steps of 0.5°C and time steps of 10 minutes.
• If you manually change the target temperature or use presets, the thermostat returns to its programmed schedule at the next schedule change.
• If the thermostat is in holiday mode, you cannot reset it from Home Assistant. To reset it, press the MENU button on the thermostat until it resets.

Troubleshooting

As the data is refreshed using an active Bluetooth connection, pollingData polling is the process of querying a device or service at regular intervals to check for updates or retrieve data. By defining a custom polling interval, you can control how frequently your system checks for new data, which can help optimize performance and reduce unnecessary network traffic. [Learn more] can fail due to connection issues.

If you see repeated connection issues, try the following:

1. Move your Home Assistant host closer to the thermostat.
2. Add ESPHome Bluetooth proxies closer to the thermostat.

Removing the integration

This integration follows standard integration removal. No extra steps are required.

To remove an integration instance from Home Assistant

1. Go to Settings > Devices & services and select the integration card.
2. From the list of devices, select the integration instance you want to remove.
3. Next to the entry, select the three dots menu. Then, select Delete.