my heater will not blow warm air into the cabin. any ideas what might be at fault and how i can rectify it.

ian wheatley, December 2009

had the same problem and it turned out to be the temperature sensor on the wing mirror (easy to replace)

Graham24, June 2010

My C5 2005 2.0hdi has started to do the same today, suspect it may be water pump (just about spins on high revs to circulate the hot water), as when I rev the car warm air comes through, also i think it may be a dicky thermostat.
Secondly maybe the internal temprature sensor not working, located near the glovebox.

Maz Aslam, December 2009