Agile said:Oh dear!
The original poster has gone away a long time ago!
I'm back folks and boy what an argument I seem to have started!
Thanks for all the posts, it's a little difficult to get a clear idea of what the consensus is though!
For clarity - I have tried the turning down the radiator valve/lockshield in the past but as I mentioned earlier it gets just as hot but takes 10 minutes for the radiator to get to full pelt instead of 5!! Not a great deal of use.
I have no reason to suspect that the stat isn't working - it clicks on and off as I would expect, just that the room gets too hot where it is.
Someone asked why the room gets so hot and what the previous owner did - well the answer is...... the hot water cylinder sits in our bedroom along with the stat! It's lagged well and in a cupboard but of course you still get a reasonable amount of heat coming out of there so add that to the rad, and especially in the mornings when there have been two people sleeping in there giving off heat and you can imagine why the stat doesn't call for heat without it being turned up high!
That's why I thought moving the stat to a more neutrally heated area of the house might work?