I am fitting a new radiator in the living room. In the other rooms I
have used TRVs to control the room temprature. In this room, however,
a TRV would be ineffective because the TRV would be covered by a
floor-length curtain, due to the position of the rad.. What other
method can I employ to control the temerature of the room? I know you
can buy in-line electric-powered valves which can be controlled by a
standard room thermostat, but is there any other method - perhaps
something that doesn't require an electric supply? How about an
in-line TRV? Are there such things?

Thanks

Frank