Help with weird old rad valve please!

[TK10]

Hi all,

First post and DIY'er, please be kind!

Just moved into a property which needs some work. Have a plasterer coming soon and need to get this rad off. Any ideas how on earth this valve works?! I've never seen one like it before. It's not moving with either a flat screwdriver or spanners, so I don't know whether it's on or off.

Any help welcomed, thank you

 

[Scott_D]

Looks like a trv and the head has come off

 

[snowhead]

I'd say it's a lockshieled valve, there would have been a cap screwed onto the thread and the slotted screw should adjust it.
However it's probably seized through lack of use.
It's possible that the part with the screw, thread, knurled nut and cap below all remove as one piece to reveal a pin valve as thermostatic valves have, the screw could possibly then be freed.

However there's a risk the valve may fall apart.

The simplest way would be to drain the system and replace the valve, and any others similar to it.