....but how do you take off the thermostatic valve??? please?

Where the plastic pieces of the control valve meet the metal fitting of the valve body there will be a circular collar, usually plastic - unscrew the collar and the TRV top will pull off.

Heres a pic...

http://lpssupplies.com/images/TRV2_B.jpg

They unscrew anticlockwise so looking down from the top where you stand it will need to be turned clockwise.

Good luck...

Peccavi
March 2009