Hi there! What exactly do u mean when u say the heater isn't working?? Has the fan stopped or does it just blow cold air??
I had a problem with the heating on a Vauxhall Cavalier, instead of blowing hot air, it blew steam!! This was because the Heater Matrix had a small hole in. (The Heater Matrix is an air/water heat exchanger much like the main Radiator in the front of your car, except instead of cooling the hot water with the cold air, it heats the cold air with the hot water). The Heater Matrix and fan is typically located inside the front centre console, (behind the heater controls and down at floor level).
It's quite fiddly to get the Heater Matrix out and replace it so I bought a bottle of Radweld and added that to my coolant system, crossed my fingers and ran the car for a while, and hey presto, it worked!! The Radweld cost about 3 pounds so it was worth a try!
Glen, December 2005