Domoticz

I have 4 electric heaters and I would like to switch them on or off in dependency with temperature sensors (netatmo and DS18B20). Is this possible by domoticz or I have to buy thermostat? I was thinking about script like "if temp is 18 turn on heater 1 (dummy switch )". Is it possible?

Yes, this is possible. All you need to know is in the Domoticz Events wiki page and in examples that will come up when you google for it.

Make sure that your setup has appropriate reliability: if you're gonna control serious heating power, you might want to add an extra safety thermostat that prevents disasters in case of control failure. Especially 433MHz wireless switches might fail to pick up an 'off' signal.

I want simple on/off control. Every heater has own line switched by SSR which is switched by relay. Now it's only controlled by time plans.

Thanks for the direction!