Anyone who has worked with Home Assistant does not want to go back: central visualisation, freely built automations, voice control and data history for every sensor. The obvious question for motorhome owners: can the Truma Combi also be integrated into Home Assistant — and if so, how?
The short answer: yes. With CampMatic your Truma Combi 4 or 6 becomes a native MQTT device that Home Assistant detects instantly via auto-discovery — as a fully-fledged climate entity, with all sensors as separate entities. No ESPHome flashing, no soldering into the LIN bus, no manual YAML.
Why Truma + Home Assistant at all?
Truma ships its own app with the iNet X system — solid, but a closed island. Anyone who uses Home Assistant has different expectations:
- One dashboard for everything: heating, inverter, solar, water tanks, door sensors — all on one surface instead of five apps.
- Automations across devices: "If outdoor temperature below 5 °C and location = pitch, set Truma to 19 °C." — that only works if the heater is in Home Assistant.
- Data history: How cold was it really at night? How much gas does the Combi use per hour of heating? Home Assistant logs it automatically.
- Voice control: Via Home Assistant Cloud you get Alexa and Google Assistant for the Truma "for free" — without Truma publishing a skill.
- No cloud dependency: MQTT runs locally. If you want, you can keep your heating data entirely inside your own network.
The three ways to bring Truma into Home Assistant
Way 1: ESPHome + solder the LIN bus yourself
The tinkerer's route. There are open-source projects on GitHub that read the Truma directly on the LIN bus with an ESP32 and a LIN transceiver IC. It works — if you bring a soldering iron, a logic analyzer and a few weekends of time. Problems:
- Intervention in the vehicle wiring — a warranty and safety topic
- The protocol is not officially documented, and any Truma firmware can break it
- No write access to all functions; depending on the project, read-only
Way 2: Mirror the Truma iNet X via an unofficial API
There are custom components that query the Truma cloud API and pass it to Home Assistant. Works as long as Truma does not change the API. Big drawback: you still need the iNet X system (€250–350), and everything runs over Truma's servers — so no local control, higher latency and an extra account.
Way 3: CampMatic with native MQTT
CampMatic speaks the Truma LIN bus out of the box and exposes all values as MQTT topics. Via Home Assistant MQTT discovery, the climate entity, sensors and switches appear automatically in the UI — without a single line of YAML.
Plug & play at the CP Plus, configured over a web UI, MQTT broker of your choice (your own Mosquitto, a Home Assistant add-on, or an external broker). More on the hardware: campmatic.de.
What you get in Home Assistant — the entities in detail
As soon as CampMatic is connected to your MQTT broker and Home Assistant subscribes to the same broker, the following entities appear automatically:
Climate entity: climate.truma_combi
- Modes:
off,heat,auto(equivalent to ECO on the CP Plus) - Target temperature in 1 °C steps
- Current indoor temperature (the CP Plus sensor)
- Fan level as
fan_mode - Hot water mode as an additional preset
That makes the Lovelace thermostat card work immediately — including slider, mode buttons and history chart.
Sensor entities
sensor.truma_indoor_temperature— current room temperaturesensor.truma_target_temperature— currently set targetsensor.truma_hot_water_temperature— boiler temperature (if present)sensor.truma_status— e.g. heating, warming up, standby, errorsensor.truma_gas_consumption— if a gas scale is pairedbinary_sensor.truma_error— reports Truma error codes
Switches and control values
switch.truma_hot_water— hot water on/off separatelyselect.truma_heating_mode— air, water, bothnumber.truma_target_temperature— target as a number entity for finer automations
Step by step: set up CampMatic in Home Assistant
1. Provide an MQTT broker
If you run Home Assistant OS or Supervised, install the Mosquitto broker add-on from the add-on store. Assign a user/password, leave port 1883. If you already have an external broker, keep using it — CampMatic is broker-agnostic.
2. Enable the MQTT integration in Home Assistant
Settings → Devices & Services → Add integration → MQTT. Enter the broker address, user and password, keep "Enable MQTT discovery" on. The discovery prefix stays at homeassistant.
3. Connect CampMatic to the broker
Open the CampMatic web UI (locally over its own hotspot or on your home WiFi), under MQTT:
- Broker host: IP of the Home Assistant host
- Port: 1883
- User / password as set in the Mosquitto add-on
- Discovery: enabled
- Topic prefix: leave the default (
campmatic/) unless two devices run in parallel
Save. After a few seconds a new device "CampMatic – Truma Combi" appears in Home Assistant with all the entities listed above.
4. Build a dashboard
A thermostat card for climate.truma_combi, a history-graph card for indoor and target temperature, plus an entities card for hot water, mode and status — and the heating dashboard is done. If you like it prettier, work with mushroom-cards or button-card.
Three automations that pay off immediately
Preheat before arrival
With the mobile app integration, Home Assistant knows your location. As soon as you come within a 10 km radius of the pitch, the heater starts:
alias: Preheat Truma on approach
trigger:
- platform: zone
entity_id: person.you
zone: zone.pitch
event: enter
condition:
- condition: numeric_state
entity_id: sensor.truma_indoor_temperature
below: 18
action:
- service: climate.set_temperature
target:
entity_id: climate.truma_combi
data:
temperature: 21
hvac_mode: heatNight setback with weather logic
A classic night setback has a catch: on very cold nights the camper cools down too much, and warming up in the morning takes forever. With Home Assistant you combine time and outdoor temperature:
alias: Truma smart night setback
trigger:
- platform: time
at: "23:00:00"
action:
- service: climate.set_temperature
target:
entity_id: climate.truma_combi
data:
temperature: >-
{% raw %}{% if states('sensor.outdoor_temperature') | float < -5 %}
18
{% else %}
15
{% endif %}{% endraw %}Error push straight to your phone
Truma reports errors on the CP Plus — but who gets up at night to check? An automation on binary_sensor.truma_error sends a push notification with the error code to your phone as soon as the heater faults. Invaluable especially when winter camping.
Voice control via Home Assistant Cloud
With a Nabu Casa subscription (or by setting up the manual Alexa/Google integration) you get voice control on top automatically: "Alexa, set the Truma to 20 degrees." — it works because climate.truma_combi is exposed as a standard climate entity. No extra skill, no Truma cloud in the path.
Frequently asked questions
Does this also work without internet at the pitch?
Yes. MQTT is local. If your Home Assistant host and CampMatic are on the same WiFi/hotspot, everything works without internet. Practically relevant if you run Home Assistant on a Raspberry Pi or mini PC in the camper.
Does the CP Plus stay usable?
Yes, always. CampMatic hooks onto the LIN bus in parallel, it replaces nothing. You can turn the CP Plus dial at any time — Home Assistant picks up the new values over MQTT and updates the UI. No getting used to a new control panel like with the iNet X panel.
Which Truma models are supported?
Truma Combi 4, Combi 4E, Combi 6, Combi 6E, Combi D6 (diesel) and Vario Heat — all models with a CP Plus from firmware C4.00.00.
What does the setup cost compared to iNet X?
CampMatic is plug-and-play and installed in under 10 minutes, without touching the control panel. The Truma iNet X system costs €250–350 and replaces the CP Plus — with installation effort. Detailed comparison: Truma iNet Box alternative.
Conclusion: Home Assistant + Truma is trivial today — if the hardware plays along
Two years ago, Truma in Home Assistant meant: soldering iron, ESP32, hacked-together YAML templates and a weekend of debugging. Today that is no longer necessary. With native MQTT support and auto-discovery, the Truma Combi is set up in Home Assistant in ten minutes — including climate entity, history, automations and voice control.
For anyone who thinks of their camper as a rolling smart home, this is the only solution that is truly open, local and free of cloud lock-in. And for anyone who later wants to integrate more — inverter, solar, door sensors, GPS tracker — Home Assistant is the platform that grows with you.
→ See CampMatic — Truma in Home Assistant over MQTT, ready in 10 minutes
Further reading:
