Looking for combination of temperature sensor and thermostat - any hints?
There are radiator valves that are thermostatically controlled that need no batteries or outside input power. They do a pretty good job of controlling the temperature of a room.Try typing "Danfoss valves" in any search engine to investigate if valves like this would suit your needs. I should ask if your heating system is hot water or steam. The valves and controller are the same for both systems unless you have an old 1 pipe steam system, The temperature sensor usually mounts on the valve it is controlling. However they have some sensors that can be mounted a few feet away.