Ford Focus 2009 TDCi

hot air has stopped working, fan blower still works in all four settings and Temp gauge seems ok on dash, when moving the dial from cold air to hot air it seems to change very slightly but its still cold air that comes out, any help would be much appreciated

PA, April 2012

thanks to the person that replied, it turned out to be a steel braid cable that is connected to the back of the control knob that selects cold/warm air.

It had a kink in it that caused it to push outwards than rather down its tube, this then meant it wasnt fully opening at the other end and wasnt letting the warm air out

PA, May 2012

Is this the 1.8 tdci?had a couple of motors but not a Focus with this engine in it and the oil cooler was blocked,the heater rad takes its feed from there,blanked off the hoses,removed from the cooler and got a hose through both pipes and flushed it out,just something to look at,have a feel of the hoses from there to the bulkhead and see if they are hot enough,another fault on these were water pump impellers sheared,just a couple of things to check,good luck

cdc, April 2012