Installation Guide
Installing
Your Hardware
Scheater only communicates with Home Assistant entities: reading temperatures, reading sensor states, and controlling radiators ON/OFF. This guide helps you choose and assemble the physical hardware necessary to build your own installation.
The Principle of Self-Installation
The advantage of Scheater is to offer the possibility of installing your own regulation system using cheap, off-the-shelf sensors and actuators. The Home Assistant ecosystem makes this task particularly easy: Scheater only depends on the entities it exposes, regardless of the hardware hiding behind them.
Required Hardware
You need an outdoor temperature sensor for the whole house, and then, for each radiator, a room temperature sensor and a smart relay. Finally, equipment to host Home Assistant completes the installation.
| Item | Quantity | Role | Required |
|---|---|---|---|
| Outdoor temperature sensor | 1 for the whole house | Provides the outdoor temperature taken into account by the regulation algorithm. | Yes |
| Room temperature sensor | 1 per room (shared if multiple radiators in the same room) | Measures the ambient temperature to be regulated. | Yes |
| Smart relay | 1 per radiator | Controls the radiator's power supply (ON/OFF). | Yes |
| 1N4007 Diode | 1 per pilot wire radiator | Allows controlling the pilot wire with a simple ON/OFF relay (see Pilot wire wiring). | If pilot wire |
| Window / door opening sensor | 1 per room (optional) | Automatically suspends heating if a window is open. | No |
| PC, Raspberry Pi 4, or server | 1 | Hosts your Home Assistant instance. | Yes |
| Zigbee USB Dongle (e.g., ZBT-1) | 1 | Zigbee network coordinator, if this protocol is chosen. | If Zigbee |
Principle Diagram for a Radiator
Each radiator relies on the same principle: sensors report their state to Home Assistant, and Scheater reads this information to decide, at any given moment, whether the radiator's relay should be activated or not.
1 for the house
1 per room
optional
+ Scheater
Pilot Wire Wiring (Example)
Here, as an example, is how my own radiators are wired — equipped with the pilot wire function — using a relay with N, L, I, and O terminals (e.g., Shelly Plus 1):
| Relay terminal | Connection |
|---|---|
N | Radiator neutral |
L and I | Radiator live (phase) |
O | 1N4007 diode to the pilot wire (the diode's bar must be oriented towards the radiator) |
With this setup, when the relay is ON, the radiator goes into Comfort mode; when it is OFF, it goes into Frost protection mode.
Choosing Your Hardware
I recommend using hardware integrable via Zigbee: the protocol is very simple to implement and low-power, which extends battery life.
Products from the Aqara range work particularly well. Sonoff products are also a good option, but read online reviews carefully: some models may lack reliability.
Example: My Personal Installation
Here, for reference, is the hardware I have been using at home for several years:
| Role | Hardware |
|---|---|
| Window opening sensor | Aqara MCCGQ11LM |
| Temperature sensor | Aqara WSDCGQ11LM |
| Relay | Shelly Plus 1 |
| Zigbee USB Dongle | ZigStar ZBStick-Pro |
| Home Assistant | Docker image, on my own server |
Integrating Your Sensors into Home Assistant
Once your radiators are wired, you still need to integrate your sensors and relays into Home Assistant. The exact procedure depends on the chosen hardware: refer to the corresponding online tutorials (Zigbee2MQTT, ZHA, or the integration specific to your manufacturer).
Example of setting up a Zigbee coordinator via Zigbee2MQTT in Home Assistant:
Creating Your Radiators in Scheater
Your hardware installation is ready and your entities are visible in Home Assistant. All that remains is to create your radiators in Scheater to be able to program them.