---
title: "Blauberg S21"
description: "Blauberg S21 is a Marketplace integration for Home Assistant. It has 52 installs sharing analytics, works locally and was last updated September 29, 2026."
canonical: "https://vulpo.app/integrations/marketplace/jvitkauskas-homeassistant-blauberg-s21"
url: "https://vulpo.app/integrations/marketplace/jvitkauskas-homeassistant-blauberg-s21.md"
last-updated: "2026-10-22"
version: "1.4"
---

# Blauberg S21

> Blauberg S21 is a Marketplace integration for Home Assistant. It has 52 installs sharing analytics, works locally and was last updated September 29, 2026.

Blauberg S21 controls a Blauberg S21 ventilation unit locally over Modbus TCP. It adds a climate entity that handles power, HVAC mode, target temperature and fan mode, with the current temperature taken from the supply outlet. Alongside it come sensors for temperatures, humidity, pressure, airflow and fan speed, plus binary sensors for filter, problem, boost, heating and cooling states. Buttons reset the filter timer and alarm, numbers set manual fan, bypass and rotor values, selects pick bypass and rotor modes, and switches cover the timer and weekly schedule. Heating and cooling activity comes from the controller's own operation bits, and all readings share one poll. Setup runs in the UI, either by choosing a device found by network discovery or by entering the host and port by hand.

Automatic summary of the README and code of jvitkauskas/homeassistant\_blauberg\_s21. Something wrong, or are you the maintainer and want your own text here? [Get in touch](https://vulpo.app/contact)

[Open in My Home Assistant](https://my.home-assistant.io/redirect/hacs_repository/?owner=jvitkauskas&repository=homeassistant_blauberg_s21&category=integration)

On Home Assistant 2026.11 or newer? [Open it in the Marketplace](https://my.home-assistant.io/redirect/marketplace_repository/?owner=jvitkauskas&repository=homeassistant_blauberg_s21&category=integration)

## Supports

- **Works locally**: Talks to your devices on your own network. No vendor cloud in between.
- **From the Marketplace**: Installed through the Marketplace, formerly HACS.
- **Actively maintained**: Its author released or pushed a change in the last six months.

## Setting it up

Install it from the Marketplace and restart Home Assistant, then add it under Settings, Devices and services.

### Enter the address

- **Host**
- **Port**

Also asked when changing the connection.

### Select a device

- **Device**

Texts from the code of [jvitkauskas/homeassistant\_blauberg\_s21](https://github.com/jvitkauskas/homeassistant_blauberg_s21).

## Entities

- **Binary sensors**: Filter needs attention, Problem, Boost active, Heating active, Cooling active
- **Buttons**: Reset filter timer, Reset alarm
- **Numbers**: Manual fan speed, Manual bypass/rotor position, Manual rotor speed
- **Selects**: Bypass mode, Rotor mode
- **Sensors**: Supply temperature, Intake temperature, Extract temperature, Exhaust temperature, Humidity, Supply pressure, Extract pressure, Supply airflow, Extract airflow, Supply fan speed, Extract fan speed, Supply fan performance, and 8 more
- **Switches**: Timer, Weekly schedule

## Troubleshooting

- **Diagnostics**: Downloads a diagnostics file to attach to a bug report.

## From the README

> Control a Blauberg S21 ventilation unit locally over Modbus TCP. Requires Home Assistant 2026.9.4 or newer (Python 3.14.2+) and uses pybls21==5.2.0.

From the README of [jvitkauskas/homeassistant\_blauberg\_s21](https://github.com/jvitkauskas/homeassistant_blauberg_s21#readme), [MIT License](https://spdx.org/licenses/MIT.html). Shortened.

## At a glance

- Kind: Marketplace integration
- Category: [Climate](https://vulpo.app/integrations/category/climate.md), Fans and ventilation
- Number: 52 installs sharing analytics; 16 GitHub stars
- Connection: Works locally
- Upkeep: Updated in the last 6 months
- Needs: Needs the Marketplace (HACS on 2026.10 and older)
- Latest version: v0.6.2, last updated September 29, 2026
- Domain: `blauberg_s21`
- Source: <https://github.com/jvitkauskas/homeassistant_blauberg_s21>
- Issues: <https://github.com/jvitkauskas/homeassistant_blauberg_s21/issues>

In Vulpo: Quick Toggle card, Climate card, Button card, Select card, Apple Watch, Control Center, Climate Live Activity (Pro)

[Widgets & Live Activities in Vulpo](https://vulpo.app/features/widgets-and-live-activities)

Independent directory, made by the developer of Vulpo. Not affiliated with Home Assistant or the Open Home Foundation. [About these numbers](https://vulpo.app/integrations/about)

Last updated 2026-10-22. Source: https://vulpo.app/integrations/marketplace/jvitkauskas-homeassistant-blauberg-s21

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