Hi, Thanks for your replies, it looks as if there is a concealed (under floor plinth) Alde finned convector radiator. Apparently these type of Alde convector radiators give 400w heat per metre as long as there is adequate venting
So need to find out length of convector radiator and if needed add more or a larger vent on the top of the boxed in section which I have been calling a plinth. Any comments advice welcome.