Anyone know anything about radiator valves ? :-). The one on the left, with the thin pin, is a spare from last time I bought a head and it basically looks exactly like all the other valves in my house. The one on the right is what's actually on my bathroom radiator and none of my TRV valve heads seem to close it correctly. The base disc with the thread seems to fit just fine, but the size and arrangement of the nut and pin Is weird looking,
