Dec 21, 2025 - 7 MIN READ

LoraWan Webasto Car Heater Controller

A LoraWan controller to interface with a webasto car heater to diy the expensive Webasto LTE controller.

Jakob Kaliwoda

The Webasto Controller is an innovative side project designed to connect an Arduino-based controller with a Webasto vehicle heater. The project demonstrates how modern IoT technology can be used to control vehicle heating systems remotely. In this example, a LoRaWAN controller is used to enable reliable long-range remote start functionality.

Want to see it in action? Watch the full demonstration here:

YouTube Demonstration Video

The project is open-source, and the source code is available on GitLab for anyone interested in replicating or improving upon the design.

Source Code

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WBusLoraRemote

A DIY alternative for the "Webasto Telestart", using two ESP32 equipped with Lora.

With a remote you can check the status, turn the parking heater and ventilation on and off with a timer.

In the car is a reciver which uses W-Bus to transfere the commands to the heater Heater-Controll-Unit. The reciver is a ESP32 with an hardware interface for the W-Bus connection.

Tested Webasto Heaters:

Webasto TT Evo 4 / 5 / 5+
Webasto TT V

I do not guarantee that this will work for your heater. Trying to recreate this project is at your own risk!

Remote:

The remote case is made to fit a Heltec ESP32 Lora V2 on a prototyping PCB with two buttons and one Power Switch.

With the oled a command can be selected. Possible commands are:

Get basic heater on/off status
Parking Heating on with Time Select
Ventilation on with Time Select
Turn both off

Planned commands:

battery level of the remote
show timers and activate or deactivate them

Controller:

Hardware Interface:

This circuit converts the TTL Output (0V - 5V) from the LevelConverter or ESP to a K-Line output signal (0V - 12V) and Kline to TTL RX (0 - 5V).

Using an ESP32 requires an "TTL-Level-Converter" to push your 3.3V output up to 5V for TX and the 5V to 3.3V input for RX. Alternative would be voltage divider.

The Circuit is a replacement for the L9637D converter chip!