Renault Scenic Heater Matrix Problems

ok so bought this car few weeks ago no problems till now!after driving for half hour or so i get a rubber burning smell through the air vents ive looked round engine and can see nothing obvious that is burning and cant really pinpoint where...

ive had a new water pump and cambelt kit - no over heating problems only leaking cooland when left overnight but not all the time had the car presaure tested for leaks by renault no leaks to be found