peugeot 306 1999 X reg, heaters not blowing hot air?

Very likely to be air in the cooling system. How many miles has the car done, have you bled all the air valves on this system, there is one on the blukhead where the hearter pipes go into the car.
checked the passengers side floor near to the centre console, as the heater matirx can leak and put coolant onto the floor, normally the carpet wil be soaked.
If the matrix has gone then this is a complete dash out job. Also the other possiblity is the headgasket and or cylinder liners gone. Bleed the system with a header tank above the height of the heater matrix inside. (Cut the bottom of a plastic drinks bottle and put the neck into the rad). MRW.

Mark
November 2010