Comparisons
Versatile Thermostat vs Smart Autotune Thermostat
SAT is built for OpenTherm boilers. Versatile Thermostat regulates each room, whatever the heat emitter, and manages everyday life in the home.
What is Smart Autotune Thermostat?
Smart Autotune Thermostat (SAT, by Alexwijn) is a HACS integration that drives a boiler through an OpenTherm or EMS-ESP gateway. It modulates the flow temperature using a heating curve and a self-tuning PID. A PWM mode also lets it drive a simple switch. It only handles heating.
Smart Autotune Thermostat official websiteFeature comparison
| Feature | Versatile Thermostat | Smart Autotune Thermostat |
|---|---|---|
| OpenTherm / EMS boiler modulation (flow temperature)Versatile Thermostat switches the boiler on or off without modulating its flow temperature. | No | Yes |
| Electric radiators, relays and pilot wire | Yes | Yes |
| Thermostatic valves, heat pumps and air conditioners (climate entities)SAT integrates valves as “rooms” that call for heat. | Yes | Partial |
| Direct control of valve opening | Yes | No |
| Outdoor temperature compensation | Yes | Yes |
| Automatic coefficient learning | Yes | Yes |
| Automatic presence via sensor | Yes | No |
| Motion detection | Yes | No |
| Open window detection via sensor | Yes | Yes |
| Automatic open window detection (temperature drop) | Yes | No |
| Power shedding | Yes | No |
| Central mode for all thermostatsSAT offers a multi-room comfort/eco mode. | Yes | Partial |
| Automatic stop / restart of heat pumps | Yes | No |
| Heating and cooling | Yes | No |
| Heating failure detection | Yes | No |
| Thermostat lock | Yes | No |
| Dedicated Lovelace card | Yes | No |
| Online log analyzer | Yes | No |
| Plugins (algorithms, cards, integrations) | Yes | No |
Comparison checked against the documentation and source code of Versatile Thermostat and Smart Autotune Thermostat (4.2.1) in October 2026. Both projects move fast: please report any mistake on GitHub.
Why choose Versatile Thermostat?
True room-by-room regulation
Each room has its own thermostat, sensor, presets and windows. The boiler only switches on when a room asks for it.
Every emitter, not just the boiler
Thermostatic valves, electric radiators and pilot wire, air-to-air heat pumps, stoves: Versatile Thermostat drives them all.
Heating and cooling
Cooling mode, automatic heat pump stop and restart, Auto-Fan: where SAT only heats.
Presence, motion and windows
Automatic switching based on presence and motion, window detection via sensor or temperature drop.
Power shedding
Essential with electric radiators: devices are cut by priority so you don't exceed your subscribed power.
Community and documentation
Full documentation in three languages, a database of tested devices and a dedicated card.
Online log analyzer
Load your logs and see temperatures, setpoints and triggers (window, safety, start-stop) on a chart. The analysis runs in your browser: your logs stay with you.
Learn moreExtensible with plugins
Since version 10, official and community plugins add regulation algorithms, cards, blueprints and integrations to fit Versatile Thermostat to your setup.
Learn more
When Smart Autotune Thermostat remains a good choice
- You have an OpenTherm or EMS boiler and want to modulate its flow temperature with a heating curve.
- You want to control the boiler's domestic hot water.
- The two tools can complement each other: SAT on the boiler, Versatile Thermostat in each room. This combination has not been officially tested yet.
Switching from Smart Autotune Thermostat to Versatile Thermostat
If you used SAT in PWM mode on a switch, simply create a “Thermostat over a switch” in Versatile Thermostat with the same switch and the same sensor: the TPI algorithm replaces the PID. If SAT drives your OpenTherm boiler, keep it for the boiler and add Versatile Thermostat on the valves in each room.
Ready to try Versatile Thermostat?
Pick your heating type and follow the tutorial: your first thermostat is up and running in a few minutes.