Hephaistos-AHA
Control your heater from your FritzBox, if you dare...
This project emulates a room thermostat for a central heating unit. It monitors a set of AVM FritzDect 301 (intelligent radiator valves) and signals the heater to turn on or off via a simple relay circuit.
Since we are dealing with mains voltage and probably gas-powered heating systems, you should not even think about using this contraption unless your are a licensed electrician and/or certified HVAC technician.
Seriously, don't.