WELL I HAVE TRYED BUT NOT SUCEEDED ! IF I SWITCH OFF ALL THE OTHER RADS IN THE HOUSE , THE COLD ONE HEATS UP ! SOMEONE SAID I NEED BIGGER PIPEWORK 22MM NOT 15MM .. I'M NOT SURE IF I LIKE THESE THERMO VALVES EITHER ! THE PIPE IS RED HOT GOING TO THE NORMAL VALVE AND I PUT THE THERMO VALVE UP...